Which of the Following Is True in the Long-Run

Multiple Choice

Which of the following is true in the long-run?

A) A firm can vary all the inputs used in production.
B) A firm can vary only one of the inputs used in production.
C) All inputs used in production are fixed in the long-run.
D) The level of output produced can be varied only over a limited range.
E) The marginal cost is at a minimum.