Which one of the following statements is correct based on the historical record for the period 1926-2007?

A:Long-term government bonds underperformed intermediate-term government bonds.

B:Inflation was less volatile than the returns on U.S. Treasury bills.

C:The standard deviation of returns for small-company stocks was double that of large- company stocks.

D:Long-term government bonds had a lower return but a higher standard deviation on average than did long-term corporate bonds.

E:U.S. Treasury bills had a zero standard deviation of returns because they are considered to be risk-free.