7) ABC Appliance offers a warranty requiring an annual fee. The warranty may be purchased at the time of sale or at any time within the first year after the appliance was purchased. ABC's president said, "Buying a warranty is voluntary and service costs differ between those purchasers who buy the warranty at the time of sale and those purchasers who wait until later to buy the warranty." What problem also faced by insurance companies is ABC concerned about, and what should happen to the warranty fee for those purchasers who wait to purchase the warranty after the initial purchase date of the appliances? A) moral hazard, warranty fee should decrease B) adverse selection, warranty fee should decrease C) moral hazard, warranty fee should increase D) adverse selection, warranty fee should increase