c
(c) Work done is equal to the potential energy stored in the wire.

\(\therefore \quad W=U=\frac{1}{2} \times\) Stress \(\times\) Strain \(\times\) Volume

OR \(\quad W=\frac{1}{2} \times Y(\text { Strain })^{2} \times\) Volume   \(……(1)\)

\((\text {Strain}=Y \times\)Strain)

Strain \(=\frac{x}{L}\)and volume \(=A L\)

\(\therefore W=\frac{1}{2} \times Y \times \frac{x^{2}}{L^{2}} \times A L \quad \Longrightarrow W=\frac{Y x^{2} A}{2 L}\)