`0.3 Kg` of hot coffee, which is at `70^(@)C`, is poured into a cup of mass 0.12 kg . Find the final equilibrium temperature. Take room temperature at `20^(@)C` .

(`s_(coffee) = 4080 J/kg-K and s_(cup) = 1020 J/kg-K`.)

A. `45.5^(@)C`

B. `55.5^(@)C`

C. `65.5^(@)C`

D. `40.5^(@)C`