Option 1: Cauline transpiration refers to the transpiration that occurs through the stem, branches, or other woody parts of a plant. This option is not the correct answer because it does not specifically refer to transpiration through leaves.

Option 2: Foliar transpiration is the correct answer. It refers to the process of transpiration that occurs through the leaves of a plant. Leaves have tiny openings called stomata, through which water vapor is released into the atmosphere during transpiration.

Option 3: Cuticular transpiration is the process of water loss that occurs through the waxy layer called the cuticle that covers the outer surface of leaves and stems. While this is a type of transpiration, it does not specifically refer to transpiration through leaves only.

Option 4: Lenticular transpiration refers to the transpiration that occurs through lenticels, which are small openings on the bark of woody stems. This option is not the correct answer because it does not specifically refer to transpiration through leaves.

Therefore, option 2 (Foliar transpiration) is the correct answer.