Which of the following is a viable way to increase a firm's GPM? Select one: a. Focus on selling a premium-priced product where customers not only pay more for higher quality materials, better service, and more innovative features, but also pay more for the brand/image of the product/firm. O b. Focus on managing the variable costs in a way that produces lower COGS, such as getting better input prices from suppliers (due to larger volume discounts) Oc. Both A & combined: Simultaneously focus on the price premium and suppressing variable costs. O d. All of the above - options A, B & C are all ways to increase a firm's GPM. Clear my choice