(b) Only two
Researchers in Indonesia have found a way to fight disease-bearing mosquitoes by breeding a species of the insect which carries a kind of bacteria that prevents viruses like dengue from growing inside them.
Wolbachia is a common bacteria that occurs naturally in 60% of insect species, including some mosquitoes, fruit flies, moths, dragonflies and butterflies. It is not, however, found in dengue-carrying Aedes aegypti mosquitoes, according to non-profit World Mosquito Program (WMP), which initiated the research.
The “Wolbachia method” is a technique used to control the spread of viral diseases transmitted by mosquitoes, such as dengue, Zika, and chikungunya. Wolbachia is a type of bacterium that can be introduced into mosquitoes to reduce their ability to transmit these diseases. When mosquitoes carrying Wolbachia mate with mosquitoes without Wolbachia, the resulting eggs do not hatch or produce offspring, thus reducing the population of disease-carrying mosquitoes. (Statement 1 is incorrect)

(c) All three
A light-year is a measurement of distance in space. The astronomical distances are measured in light-years because, the speed of light is constant throughout the universe and is known to high precision. In a vacuum, light travels at 670,616,629 mph (1,079,252,849 km/h). To find the distance of a light-year, you multiply this speed by the number of hours in a year (8,766). The result: One light-year equals 5,878,625,370,000 miles (9.5 trillion km). At first glance, this may seem like an extreme distance, but the enormous scale of the universe dwarfs this length.
Measuring in light-years also allows astronomers to determine how far back in time they are viewing. Because light takes time to travel to our eyes, everything we view in the night sky has already happened. In other words, when you observe something 1 light-year away, you see it as it appeared exactly one year ago.

(c)
Fractional Orbital Bombardment System (FOBS): The idea behind FOBS is, that a warhead is put into a stable orbit and it deorbits over the target. If the target and the launch position are lined up and the warhead keeps going round, it will complete a circle. Obviously, with the earth moving during this, it is more of a spiral than a ring, but the horizontal movement is countered in such a way that the warhead still goes over the target. The real point is that missile can be flown directly to the target, or it is fired in the opposite direction the other way around the planet and still arrive at the target from the opposite direction over the South Pole instead of the North Pole, where almost all of North America’s early warning systems are pointed. More importantly, the warhead can remain in orbit for days or months so that when the weapon deorbits and attacks its target or simply explodes in orbit, an EMP pulse is generated, which initiates an attack.

(d) They protect the body from the diseases caused by pathogens.
B cells and T cells are part of the immune system that helps protect the body from harmful substances such as pathogens and toxins.
However, they are not specifically designed to protect against environmental allergens. Instead, the immune system sometimes mistakenly identifies harmless substances like pollen or dust mites as threats, leading to an allergic reaction.
While B cells and T cells play a role in the body’s inflammatory response, they do not directly alleviate pain or inflammation.
In fact, certain types of T cells can contribute to inflammation, which is a normal part of the body’s response to injury or infection. They are not typically involved in pain management. B cells and T cells are not immunosuppressants.
They are key components of the immune system that help protect the body against infections.
However, some specific subtypes of T cells, known as regulatory T cells, can suppress the immune response to prevent it from attacking the body’s own cells, thereby playing a role in preventing autoimmune diseases.
B cells and T cells are crucial components of the immune system.
B cells produce antibodies that can recognize and neutralize foreign substances (antigens), such as bacteria and viruses. T cells can directly kill infected cells or help other immune cells perform their functions. Together, they play a vital role in protecting the body from diseases caused by pathogens.

(d) 1 and 2 only
A combination reaction is a reaction where two or more elements or compounds combine to form a single compound. Calcium oxide combines with water to form calcium hydroxide. Hence, it is a combination reaction.
It is an exothermic reaction as a lot of heat liberate with hissing sound during the reaction.