How is sunlight used in photosynthesis?
sunlight controls the amount of water in plant cells.
sunlight is a nutrient for plants.
sunlight is converted to chemical energy.
sunlight breaks cell walls to allow energy in and out.

Option B, Sunlight is converted to chemical energy

Explanation:

The energy from sunlight is used in the process of photosynthesis to convert chemical compounds like carbon dioxide and water into glucose, oxygen and ATP. Adenosine Tri Phosphate (ATP) is the major source of energy in all living organisms. ATP provides power/energy to carry out all other cellular/metabolic process with in a living organism. Also, solar energy is entrapped chemical energy in food (glucose & other sugar etc.) produced by chlorophyll containing organism such as plants, algae, cyanobacterias etc.

Thus, option B is correct  

the flagellates share a facultative mutualist association with termites. mutualism is a biological interaction between individuals of different species, where both benefit from each other. this is called cooperation and it differs from other interactions such as cases of exploitation, such as parasitism, predation. in this interaction called association, both species cooperate and benefit.