An investor buys 1 share of Zephyr Ltd at the price of $34.5 on July 1, 2021. The firm is not expected to pay any dividends. Consider the following three possible scenarios for the share price on July 1, 2022: $58 if the economy is "good", with a probability of 30%. $36 if the economy is "moderate", with a probability of 55%. $22.5 if the economy is "bad", with a probability of 15%.

a) Calculate the expected return for holding the share for a year.

b) Calculate the variance of return and standard deviation of return.

c) Explain the concept and benefits of portfolio diversification. Is it possible to diversify away all risk in a portfolio? Explain your answer.