Holding All Else Constant,a Decrease in the Market Demand for a Product

Multiple Choice

Holding all else constant,a decrease in the market demand for a product in a competitive market would cause:

A) the average total cost (ATC) curve of the firms to decrease.
B) an increase in the price a firm could charge for the product.
C) the marginal cost (MC) curve of the firms to decrease.
D) the marginal revenue (MR) curve of the firms to shift downward/leftward.
E) an increase in profits for the firm.