Leaf tendrils are found in

Concept: Tendrils are essentially modified stem or leaf that has a string-like shape that helps plants for the climbing portions of plants.
A leaf tendril is a specific plant organ that has a twining development that circles any object it experiences.
A leaf tendril in peas are really changed leaves that arise through a leaf node, and it has a wiry and coiled structure that encircles and upholds the plant.

In grapevine, stem tendrils are modified apical buds, and in cucumber, stem tendrils are modified auxiliary buds. Pea has leaf tendrils.

Hence, option A is the correct answer.