Petiole is modified into tendril in
A. Passiflora
B. Gloriossa
C. Pisum
D. Clematis

Hint: There are various parts of the leaf that modify into tendrils in plants. In some plants the petiole is modified to form the tendril so it also facilitates in climbing. They are found in temperate regions and rarely in tropics.

Complete answer:
> The petiole is a stalk that connects the blade (the extended part of the leaf) with the leaf base. A tendril is a thread like structure which facilitates the climbing in plants and also provides support to the plant. Tendrils are modified stem, leaf or petioles. They help in support and attachment by clasping and gripping nearby objects. Examples are Clematis and Tropaeolum.
> In plants, either leaf, upper leaflets, terminal bud, petiole or stipule gets modified into tendril.
> In lathyrus, the entire leaf is modified into tendril. In pisum, the upper leaflets are modified into tendrils.
> In passiflora, the terminal bud is modified into tendril.
> In gloriosa, the leaf tip is modified into tendril.
> In clematis, the petiole is modified into tendril. In this leaves are opposite and divided into leaflets and leaf stalks that twist and curl around supporting structures to anchor the plant as it climbs. They are mainly found throughout the northern hemisphere (temperate regions). The wild Clematis species native to china made their way into Japanese gardens by the 17th century.

Note: Tendrils, plant organ specialized to anchor and support vining stems. A petiole attaches the leaf to the stem and contains vascular tissue that provide a connection from stem to permit sap to enter the leaf and the products of photosynthesis (carbohydrates) to be transported from the leaf to the rest of the plant.