Which of the following statements is correct?

Select one:

a.

Portfolio diversification reduces the variability of the returns on the individual stocks held in the portfolio.

b.

If an investor buys enough stocks, he or she can, through diversification, eliminate virtually all of the nonmarket (or company-specific) risk inherent in owning stocks. Indeed, if the portfolio contained all publicly traded stocks, it would be riskless.

c.

The required return on a firm's common stock is determined by its systematic (or market) risk. If the systematic risk is known, and if that risk is expected to remain constant, then no other information is required to specify the firm's required return.

d.

A security's beta measures its nondiversifiable (systematic, or market) risk relative to that of an average stock.

e.

A stock's beta is less relevant as a measure of risk to an investor with a well-diversified portfolio than to an investor who holds only that one stock