You decide to purchase 700 shares of the ARKK ETF using 50% margin. The current price of the ARKK ETF is $310 per share. Assume that all interest rates are zero. If the price of the ARKK ETF falls to $280, what is the rate of return on your investment (assuming no distributions)? A) -19.36% B) -9.68% C) 19.41% D) 38.82%