Answer:
The correct answer would be C) freezing temperatures
Photosynthesis is the natural process by which plants synthesized their food with the help of sunlight and chlorophyll.
The carbon dioxide and water are the substrate and glucose and oxygen are the products to this process.
Increase in the amount of sunlight, carbon dioxide increases the rate of photosynthesis until the maximum rate of photosynthesis is achieved.
However, temperature shows the bell-shaped curve when it is placed against the photosynthesis rate. The photosynthesis rate is efficient under optimum temperature range. Beyond this range, that is, extreme temperature (whether extreme heat or cold) decreases the rate of the photosynthesis.
