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.
