A wire of natural length `l`, young's modulus `Y` and area of cross-section `A` is extended by `x`. Then, the energy stored in the wire is given by

Options

A. `(1)/(2)(YA)/(l)x^(2)`
B. `(1)/(3)(YA)/(l)x^(2)`
C. `(1)/(2)(Yl)/(A)x^(2)`
D. `(1)/(2)(YA)/(l^(2))x^(2)`