Carl and Florence Lyles have the option of investing their $20,000 in a four-year CD with 5.15% interest compounded annually, 5% interest compounded daily, 5.25% interest compounded monthly, or 5.5% interest compounded quarterly. Which would be the best investment?
a) 5% compounded daily
b) 5.5% compounded quarterly
c) 5.25% compounded monthly
d) 5.15% compounded annually