how to calculate diversifiable risk and non- diversifiable risk ? (part b & part c )

1. Assume the required return on the following companies' shares are as follows: Company A B D Required return 18% 22% 15.5% 19.2% If the expected return on the market portfolio is 13% and the risk- free rate of return is 2%, answer the following: a) Which company has higher sensitivity of return on its share in response to 1% change in return on the market portfolio? I b) Which share possesses a higher diversifiable risk? c) Which share possesses a higher non-diversifiable risk? d) Which share pays a higher risk premium