Correct answer is A. Please explain how to solve.

3. If markets are perfect (and using the other assumptions in Miller and Modigliani (1961)), stock prices should fall by the amount of a cash dividend. If so, can a firm make its stockholders wealthier by changing (i.e., increasing or decreasing) its dividend? A. No, under these assumptions, a firm cannot make its stockholders wealthier by changing its dividend. B. Yes, under these assumptions, a firm can make its stockholders wealthier, but only by increasing its dividend. C. Yes, under these assumptions, a firm can make its stockholders wealthier, but only by decreasing its dividend