According to the passage, which of the following is true of the 'factors affecting employers' that are mentioned in lines 5 ?
A.
Most experts cite them as having initiated the growth in temporary employment that occurred during the 1980's.
B.
They may account for the increase in the total number of temporary workers during the 1980's.
C.
They were less important than demographic change in accounting for the increase of temporary employment during the 1950's.
D.
They included a sharp increase in the cost of labor during the 1980's.