Factors Affecting Photosynthesis — Prelims Questions

Which of the following statements is INCORRECT regarding the factors affecting photosynthesis?

A plant is exposed to optimal light intensity and temperature, but its photosynthetic rate is still low. Which of the following is most likely the limiting factor?

A C3 plant is kept in a greenhouse where light intensity is gradually increased. The rate of photosynthesis increases initially but then plateaus. If the $CO_2$ concentration is then doubled, the rate of photosynthesis increases further. This observation best illustrates:

Which of the following conditions would lead to the highest rate of photosynthesis in a C4 plant?

If the concentration of $CO_2$ in the atmosphere decreases significantly, which type of plant would be more adversely affected in terms of photosynthetic efficiency?

A student observes that a plant's photosynthetic rate increases linearly with increasing light intensity up to a certain point, after which the rate remains constant despite further increases in light. Which of the following is the most appropriate explanation for the plateau phase?