Stomata Admit CO₂ to the Leaf Interior but Also Facilitate

Stomata admit CO₂ to the leaf interior but also facilitate the loss of water from the leaves; plants must regulate their stomata carefully or risk dehydration.A reasonable hypothesis associated with the global increase in atmospheric CO₂ is that plants will

A) evolve lower stomatal densities to reduce the potential for desiccation.
B) grow smaller and more slowly than they do now.
C) keep their stomata closed most of the time to minimize carbon dioxide poisoning.
D) increase their stomatal densities to take advantage of the abundance of CO₂ .