`50 gm `of copper is heated to increase its temperature by `10^(@)C.` If the same quantity of heat is given to `10 gm `of water, the rise in its temperature is (Specific heat of copper`=420 Joule-kg^(-1)@C^(-1)`
A. `5^(@)C`
B. `6^(@)C`
C. `7^(@)C`
D. `8^(@)C`