What happens when light intensity is increased beyond a certain limit on a plant?

Assertion : The atmospheric concentration of $CO_2$ at which photosynthesis just compensates for respiration is referred to as $CO_2$ compensation point.
Reason : The $CO_2$ compensation point is reached when the amount of $CO_2$ uptake is less than that generated through respiration because the level of $CO_2$ in the atmosphere is more than that required for achieving $CO_2$ compensation point.

Generally,atmospheric $CO_2$ is not a limiting factor for hydrophytes because...

Which of the following factors affecting photosynthesis does not have a direct effect on the process?
$I$. Light
$II$. Water
$III$. Temperature
$IV$. Carbon Dioxide
Select the correct option.

The rate of photosynthesis is maximum in the $P$ region of light and minimum in the $Q$ region of light.

Increase in $CO_2$ concentration around the leaf results in: