An investor holding a well-diversified portfolio is considering investing in shares of Microsoft common stock. For the well-diversified investor, what is the appropriate measure of the risk for Microsoft common stock? O A. The standard deviation of Microsoft common stock O B. Microsoft's correlation with the high tech stocks in the portfolio. C Zero as all the nsk of Microsoft stock IS diversified away in the well diversified portfolio. D. OE. The serial covariance in the returns of Microsoft stock The covariance of Microsoft stock with the well-diversified portfolio