You are given the following three money market securities: A US T-bill offering a quoted yield of 6.75%; A bank CD offering a quoted yield of 7.56%; A MA Municipal bond offering a quoted yield of 4.25%; You pay Federal tax at the rate of 32%, and the MA state tax at the rate of 6.25%. It is estimated that the US T-Bill has zero risk of default, the MA municipal has a 1.8% chance of default, and the back CD has a 2.3% chance of default. The quoted yield is before tax and credit risk adjustments, which of these three securities is best after adjusting for tax and credit risk?

a. Bank CD

b. cannot make decision

c. T-Bill

d. They are the same

e. MA Municipal