Market share refers to a. the ratio of sales revenue of the firm to the total sales revenue of all firms in the industry, including the firm itself. b. the ratio of the profit of the firm to the total profits of all firms in the industry, including the firm itself. c. the ratio of sales revenue of the firm to the total sales revenue of all firms in the industry, excluding the firm itself. d. the ratio of the profit of the firm to the total profits of all firms in the industry, excluding the firm itself. e. the ratio of the profits of all firms in an industry to the profits of the firm.