A metal rod of cross-sectional area `10^(-4)m^2` is hanging in a chamber kept at `20^@C` with a weight attached to its free end. The coefficient of thermal expansion of the rod is `2.5xx10^(-6)K^(-1)` and its Young's modulus is `4xx10^(12)N//m^2`. When the temperarure of the chamber is lowered to T then a weight of 5000 N needs to be attached to the rod so that its length is unchanged. Then T is

Options

A. `15^@C`
B. `12^@C`
C. `5^@C`
D. `0^@C`