According to statistics, the American industry annually loses______ owing to its employees'backaches.

A．employees' physical fitness is a factor of production
B．employees' physical fitness improves industrial performance
C．industry develops along with corporate physical fitness programs
D．there is a market need for corporate physical fitness

A．will gladly join in the fitness program
B．have realized the need of effective measures
C．have carried research into the causes of profit losses
D．have come to see backaches are the greatest cause for the losses