Main idea: When stocks appreciate in value a profit is realized. Which of the following details supports the main idea? A. The purchase price of the common stock was $7.50 per share; after four years it was sold at $13 per share for profit of $550. B. When stocks appreciate $6.50 per share, they should be sold. C. It is necessary to purchase 100 shares of common stock to make a $550 profit. D. To realize a profit, stock must be held four years.