Hi,

Recall from the first sentence in the second paragraph of the passage:

To return to a depolarized state after light stimulation, photoreceptors must undergo recovery which is largely dependent on the synthesis of new cGMP by RetGC.

This implies that an increase in RetGC results in an increase in recovery.

Later in the paragraph, it is mentioned that RetGCs are inhibited in the dark, while they are stimulated to produce cGMP in the light.

This will eliminate B and C as pupil constriction will promote a dark environment that inhibits RetGCs and therefore photoreceptor recovery.

Next, we recall from memory that adrenergic signalling dilates your pupils in a fight or flight response, eliminating D and leaving A.

If you wanted more of an internal check, it makes sense that your photoreceptors would recover faster in the light, because in the dark they have nothing to recover from as they are not getting stimulated as much to begin with, and your photoreceptors can only recover following stimulation.

Please let me know if anything is unclear.