ABC Corporation Corporation's (a large manufacturing firm) gross profit margin is much larger than the other firms in the industry. Which of the following is the most likely explanation? Firm A has a very old, very inefficient production facility. Firm A faces a higher tax rate. Firm A uses too much middle management. Firm A is the only firm in the industry that does not offer a 2-year warranty on their product Firm A has the only non-unionized workforce in the industry