The drinking water needs of an office are met by cooling tab water in a refrigerated water fountain from 23 to 6°C at an average rate of 10 kg/h. If the COP of this refrigerator is 3.1, the required power input to this refrigerator is
(a) 197 W
(b) 612 W
(c) 64 W
(d) 109 W
(e) 403 W