Q$\mathrm{.}5$ Experimental measurements on a refrigeration system indicate that rate of heat extraction by the evaporator, rate of heat rejection in the condensor and rate of heat rejection by the compressor body to environment are $70$ kW$,90$ kW and $5$ kW respectively. The power input $($in kW$)$ required to operate the system is

$($a$)15$

$($c$)25$

$($b$)20$

$($d$)75$