Which of the following is not true? 2 parts (select one out of each part)

1st part

a)The risks associated with investing in a stock can be somewhat mitigated through diversification, although systematic risks cannot be mitigated.

b) Systematic risks refers to the type of risks that is specific to a given company or industry specifically.

c) A stock's total dollar return incorporates both the impact from the change in stock price and dividend payments.

d) None of the above (all of the above are correct).

2nd part

a) A geometric average return is more reliable for the purpose of gauging the long-term performance of the stock (that is, the stock's performance over time) than the arithmetic average.

b) A stock's risk premium is defined as the stock's return subtracted by the risk-free rate.

c) The type of efficient market hypothesis that is most often used to forecast stock prices is called the weak form of the efficient market hypothesis.

d) None of the above (all of the above are correct).