What is the difference between soft manufacturing and flexible manufacturing?

Select one:

a. Flexible manufacturing has been shown to be more effective than soft manufacturing.

b. Soft manufacturing is based on the idea that machines can generally do better work than humans, while flexible manufacturing is based on the opposite assumption.

c. Soft manufacturing emphasizes smaller groups of machines than flexible manufacturing does.

d. Flexible manufacturing emphasizes efficiency, while soft manufacturing emphasizes effectiveness.

e. There are no differences between the two concepts.