Can you explain why the answer is c

return? a) 3.3% b) 3.5% C) 2.7% d) 2.1% 3. When stocks are combined into a portfolio according to the same weights: a) the expected return of the portfolio is less than the arithmetic average expected return of the stocks due to risk diversification. b) the expected return of the portfolio is greater than the arithmetic average expected return of the stocks due to risk diversification. c) the expected return of the portfolio is equal to the arithmetic average expected return of the stocks. d) there is no relationship between the expected return of the portfolio and the expected return of the stocks