Assume BGL Enterprises increases its operating efficiency by lowering its costs while holding its sales constant. As a result, given all else constant, the: I HAVE THE ANSWER BUT NEED AN EXPLANATION...

Assume BGL Enterprises increases its operating efficiency by lowering its costs while holding its sales constant. As a result, given all else constant, the:I HAVE THE ANSWER BUT NEED AN EXPLANATION AS TO WHY THIS IS THE CORRECT ANSWER

A.        return on assets will decrease.

B.        profit margin will decline.

C.        equity multiplier will decrease.

D.        return on equity will increase.

E.        price-earnings ratio will increase.