To estimate the expected return on equity investments:

A) it is necessary to look only at recent data on stock returns.
B) one needs to look only at expected returns on debt instruments.
C) would require a study of stock market returns for many decades.
D) would require only a course in financial economics.

To estimate the expected return on equity investments, one needs to study stock market returns for many decades. It is not sufficient to look only at recent data on stock returns or expected returns on debt instruments. A course in financial economics may provide some useful knowledge, but studying historical stock market returns is essential for estimating the expected return on equity investments.