There is one incorrect statement among the following. Which one is it?

A. High company specific risk results in high beta.

B. If two stock returns are perfectly positively correlated, then there is no risk-diversification benefit by combining these two assets in a portfolio.

C. A portfolio of 30 stocks are generally considered fully diversified.

D. If standard deviation of returns is very high, then actual return next year may be quite different from average return compared to the case where standard deviation is very low.