What three factors affect the rate of photosynthesis? (DO NOT GOOGLE I can tell if you did)

The major factors that affect the rate of photosynthesis are the carbon dioxide levels, water and amount of light. Also Temperature

If any of these are low the rate of photosynthesis would decrease.

i believe it's c. the trait for large beaks will be passed on to future generations through natural selection.

since eventually smaller beaks would have to find another source of food or even eventually just die out from the lack of food.