The correct options are
A Photosynthesis
B Transpiration
C Exchange of gases
Coating of leaves with oil will block the stomatal opening present on the leaf. This will prevent the exchange of gases and the transpiration process. This will also disrupt the photosynthesis process as no gaseous exchange can take place. Whereas the water is absorbed by the roots of the plants. So, absorption of water will not be affected if the leaves are coated with oil.