Can you please explain why D is correct and why E is not. I know that all the other options are wrong.

Thanks

Question 17. Stock A has an expected return of 12%, a beta of 1.2, and a standard deviation of 20%. Stock B also has a beta of 1.2, but its expected return is 10% and its standard deviation is 15%. Portfolio AB has $900,000 invested in Stock A and $300,000 invested in Stock B. The correlation between the two stocks' returns is zero (that is, rA,B = 0). Which of the following statements is CORRECT? a. Portfolio AB's expected return is 11.0%. b. Portfolio AB's beta is less than 1.2. c. Portfolio AB's standard deviation is 17.5%. d. The stocks are not in equilibrium based on the CAPM; if A is valued correctly, then B is overvalued. e. The stocks are not in equilibrium based on the CAPM; if A is valued correctly, then B is undervalued. Please show work / formulas in excel