Question 4 a) Define non-diversifiable risk. Explain why, in theory, non-diversifiable risk is considered the only relevant risk for determination of an investor's required return on a risky asset? (1+2-3 marks) b) What is the efficient market hypothesis? Discuss the three forms of the efficient market hypothesis. (2+3=5 marks) c) Briefly describe the following types of mergers: i) horizontal, ii) vertical, iii) congeneric and iv) conglomerate. (0.54-2 marks)