Photosynthesis Requires Sunlight and Water

Photosynthesis requires sunlight and water. Leaves are broad and flat to maximize exposure to the sun, but how do they retain water since all that sunlight should cause a lot of evaporation?

A) They don't need to worry about retaining water because the xylem keeps them constantly supplied from the roots.
B) They don't need to retain water because if the plant doesn't have enough water it will wilt and not photosynthesize anyway.
C) They retain water by opening their stomata and having a waxy coating.
D) They retain water by closing their stomata and having a waxy coating.
E) They don't need to worry about retaining water because when it rains they can store enough that it doesn't matter if there is evaporation.