Correct option is B
Correct Answer:
Option 2
Explanation: At higher temperatures (around 40 °C), the affinity of
Rubisco for O₂ increases relative to CO₂ in C₃ plants. This enhances
oxygenase activity, leading to increased
photorespiration. Photorespiration consumes previously fixed carbon and energy, thereby
reducing net CO₂ fixation and productivity. Options 1 and 3 are incorrect because photorespiration increases (not decreases) and stomata tend to partially close at high temperatures to prevent water loss. Option 4 applies to
C₄ plants, not C₃ plants.
