Whenever Average Variable Cost Is Declining with Increases in Output

Multiple Choice

Whenever average variable cost is declining with increases in output:

A) marginal cost is always declining as average total cost declines.
B) average total cost at first decreases and then increases with output.
C) marginal cost is always declining as average total cost increases.
D) marginal cost at first decreases and then increases with output.
E) marginal cost at first increases and then decreases with output.