An Economist Observed That, as More Computers Are Added to a Factory

Multiple Choice

An economist observed that, as more computers are added to a factory, the costs of production initially decline, reach a minimum, and then rise. In a diagram that has costs on the vertical axis and the number of computers on the horizontal axis, the relationship always is

A) negative both before and after the minimum point.
B) negative and then positive after the minimum point.
C) negative and then linear after the minimum point.
D) positive and then negative after the minimum point.
E) linear and then positive after the minimum point.