The correct options are
A Transpiration
C Photosynthesis
Key role of the leaves are: transpiration and photosynthesis.
∙ The process through which the excess water is released through stomata in the form of vapour is known as transpiration.
∙ The process by which green plants synthesise food for themselves using carbon dioxide and water in the presence of sunlight is known as photosynthesis. A green pigment, chlorophyll help in absorption of sunlight.