Which of the following scenarios is consistent with an increasing cost of goods sold to sales percentage and increasing inventory turnover? O a. Firm raises prices to increase its gross margin but inventory sells more slowly. O b. Weak economic conditions lead to reduced demand for a firm's products, necessitating price reductions to move goods. c. Strong economic conditions lead to increased demand for a firm's products, allowing price increases. d. Firm shifts its product mix toward lower margin, faster moving products