The phrase "calls for" ( Para. 3 ) means _______.

A．wages should be paid on the basis of length of service
B．the benefit of the increased production and lower costs should be shared by workers
C．supplementary unemployment benefit plans should be promoted
D．the transition to automation should be brought about with the minimum of inconvenience and distress to workers

A．will eventually prevent unemployment
B．will help workers acquire new kills
C．will eventually benefit the workers no less than the employers
D．is a trend which cannot be stopped