Air at $$20^\circ C$$ blows over a plate of $$50 cm \times 75 cm$$ maintained at $$250^\circ C.$$ If the convection heat transfer coefficient is $$ 25W/m^{2^\circ} C$$ , the heat transfer rate is

A

2.156 kW

B

2156 kW

C

215.6 kW

D

21.56 kW