You opened a margin account with a brokerage firm and purchased 300 shares of COF for $150 per share and deposit initial margin of 60%.The next day, COF's price rises to $160 per share the next day. What are your actual margin and rate of return on your investment? a) 50%; 6.67% Ob) 50%; 11.11% OC) 62.5%; 6.67% d) 62.5%; 11.11% e) 55%; 6.67%