Correct Answer (Detailed Explanation is Below)
A.
Gas exchange and regulation of transpiration
Detailed Explanation
Stomata regulate gas exchange and transpiration. Carbon dioxide enters leaves for photosynthesis, while oxygen and water vapour can leave through stomatal pores. Their opening is influenced by factors such as
light, carbon dioxide concentration, water availability and hormones such as abscisic acid (ABA). Thus stomata help balance photosynthesis with water conservation.