An absorption air-conditioning system is to remove heat from the conditioned space at 20°C at a rate of 90 kJ/s while operating in an environment at 35°C. Heat is to be supplied from a geothermal source at 140°C. The minimum rate of heat supply is

(a) 13 kJ/s

(b) 18 kJ/s

(c) 30 kJ/s

(d) 37 kJ/s

(e) 90 kJ/s