Assume That Interest Rates on 15-Year Noncallable Treasury and Corporate $\begin{array}{ll}\text { T-bond }=7.72 \% & \mathrm{~A}=9.64 \% \\\mathrm{ALA}=8.72 \% & \mathrm{BBB}=10.18 \%\end{array}$

Multiple Choice

Assume that interest rates on 15-year noncallable Treasury and corporate bonds with different ratings are as follows: $\begin{array}{ll}\text { T-bond }=7.72 \% & \mathrm{~A}=9.64 \% \\\mathrm{ALA}=8.72 \% & \mathrm{BBB}=10.18 \%\end{array}$ The differences in rates among these issues were most probably caused primarily by:

A) Tax effects.
B) Default risk differences.
C) Maturity risk differences.
D) Inflation differences.
E) Real risk-free rate differences.