Solution

A. Xylem: It is the chief conductor of vascular plants responsible for conduction of water and inorganic solutes.
B. Sclerenchyma: Young cells are living but mature cells become dead due to deposition of impermeable secondary wall.
C. Collenchyma: Cells of collenchyma contain protoplasm and are living. The tissue has the capacity to expand and gives tensile strength to the body.
D. Epidermis: The epidermal cells vary in their shape and size. they are generally compactly arranged forming a continuous layer, interrupted only by stomata.

So, the correct answer is 'Collenchyma'.