An investor puts up $20,000 but borrows an equal amount of money from his broker to double the amount invested to $40,000. The broker charges 4% on the loan. The stock was originally purchased at $40 per share, and in 1 year the investor sells the stock for $44. The investor's rate of return was 0 6,00% o 16.00% o 8.00% 12.00%