A company has accepted a contract to produce a special electric motor. The number of direct labour hours required to produce the first motor is 250. If an 85% learning curve applies to the production of motors, then the number of labour hours needed to produce the 4th motor is
A) 212.5 hours.
B) 180.6 hours.
C) 153.5 hours.
D) 0 37.5 hours