Which of the Following Statements Is Most Correct

Which of the following statements is most correct?

A) The beta coefficient of a stock is normally found by running a regression of past returns on the stock against past returns on a stock market index. One could also construct a scatter diagram of returns on the stock versus those on the market, estimate the slope of the line of best fit, and use it as beta.
B) It is theoretically possible for a stock to have a beta of 1.0. If a stock did have a beta of 1.0, then, at least in theory, its required rate of return would be equal to the riskless (default-free) rate of return, rRF.
C) If you found a stock with a zero beta and held it as the only stock in your portfolio, you would by definition have a riskless portfolio. Your 1-stock portfolio would be even less risky if the stock had a negative beta.
D) The beta of a portfolio of stocks is always larger than the betas of any of the individual stocks.
E) All of the statements above are true.