An investor buys 200 shares of ABC at the market price of $100 on full margin. The initial margin requirement is 40 percent and the maintenance margin requirement is 25 percent. If the shares of stock later sold for $ 200 per share, what is the rate of return on the margin transaction（）

A. minimum amount of funds that must be supplied when purchasing a security on margin.
B. amount of liquidity that must be maintained in a margin account.
C. amount of cash that an investor must maintain in his/her margin account.

A. A price-weighted index assumes the investor holds an equal number of shares of the stocks in the index.
B. Tests of market efficiency find that stock exchange specialists derive above-average returns.
C. The bulk of all bond trading takes place on organized exchanges.