A Force Of $15.0 \mathrm{~N}$ Is Applied to a Wire with an Unstretched Length Of with an Unstretched

A force of $15.0 \mathrm{~N}$ is applied to a wire with an unstretched length of $4.00 \mathrm{~m}$ and a diameter of $5.00 \mathrm{~mm}$ . If the wire changed length by $1.20 \mathrm{~mm}$ , then the strain in the wire is

A) $5.00 \times 10^{-4}$ .
B) $2.00 \times 10^{-4}$ .
C) $3.00 \times 10^{-4}$ .
D) $1.00 \times 10^{-4}$ .
E) $4.00 \times 10^{-4}$ .