Bonnie wants to buy a top-of-the-line sewing machine that does embroidering and fancy stitching for $1,000. She can buy it on her credit card and pay interest of 12 percent on it for a year or she can cash in a bond that she has had for many years that is worth $1,000 and earns seven percent interest and pay cash for the machine. How much does she save in net interest cost (explicit minus implicit) for the year if she sells the bond and pays cash? O A. $70 B. $120 C. $60 D. $50