Which of the following statements is TRUE? "When trading securities, ..." a. The ask price is greater than the bid price, and the investor buys at the ask price. b. The ask price is greater than the bid price, and the investor buys at the bid price. c. The bid price is greater than the ask price, and the investor buys at the bid price. d. The bid price is greater than the ask price, and the investor buys at the ask price