Which Statement Is Descriptive of the Long Run

Which statement is descriptive of the long run?

A) The firm must pay an electric bill that varies each month as well as a mortgage payment of $10,000 per month.
B) The firm is trying to increase its amount of output by adding an extra shift so that its equipment is in use more hours of the day.
C) A firm is deciding how much of its equipment to sell so that it can reduce its monthly loan payments for equipment.
D) A firm is deciding how many workers to use in its production line.