can someone help me solve these questions with explanation ?

Consider the following scenario analysis and answer the following 3 questions: Economy Probability Return on Stock A Return on Stock B Good 20% 20% 20% 30% Normal 50% 15% 10% Bad 30% 10% 5% 18. What are the expected return and standard deviation of stock A? A) 13.5% and 3.5% B) 14.5% and 3.5% C) 11% and 14.3% D) 10% and 13.3% 19. What are the expected return and standard deviation of stock B? A) 17% and 8.2% B) 17% and 6.5% C) 12.5% and 9.0% D) 12.5% and 3.1% 20. What's the correlation coefficient between the two stocks? A) 0.9 B)-0.8 C) -0.9 D) 0.8 21. In the mean-standard deviation graph, which one of the following statements is true regarding the iso-utility curve of a risk averse investor? A. It is the locus of portfolios that have the same expected rates of return and different standard deviations. B. It is the locus of portfolios that have the same standard deviation and different rates of return. C. It is the locus of portfolios that offer the same utility according to returns and standard deviations. D. It connects portfolios that offer increasing utilities according to returns and standard deviations. 22. The Capital Allocation Line provided by a risk-free security and N risky securities is A. the line that connects the risk-free rate and the global minimum-variance portfolio of the risky securities. B. the line that connects the risk-free rate and the portfolio of the risky securities that has the highest expected return on the efficient frontier. C. the line tangent to the efficient frontier of risky securities drawn from the risk-free rate. D. the horizontal line drawn from the risk-free rate