The S&P 500 index delivered a return of 25%, -5%, 25%, and 10% over four successive years. What is the arithmetic average annual return per year? A. 16.5% B. 20.63% C 15.13% OD. 13.75% Suppose you have $10,000 in cash and you decide to borrow another $10,000 at a 8% interest rate to invest in the stock market. You invest the entire $20,000 in an exchange-traded hund (ETF) with a 11% expected retum and a 20% volatility Assume that the ETF you invested in retums - 10%. Then the realized return on your investment is closest to A-25% OB -20% OC -11% OD -28%