The food compartment of a refrigerator is maintained at $3C$ by removing heat from it at a rate of $6k\frac{J}{s}.$ If the required power input to the refrigerator is $2\mathrm{.}5kW,$ the rate of heat rejection to the room that houses the refrigerator is

Select one:

a$.8\mathrm{.}5kw$

b$.5\mathrm{.}5kw$

c$.7\mathrm{.}5kw$

d$.2\mathrm{.}4kw$