13. last year, stacy purchased 81 shares of stock a at $55 per share, 64 shares of stock b at $57 per share, and a ten-year $3500 bond with a 6.16% coupon for $3100. stacy sold both stocks today. stock a is worth $61 per share and stock b has a value of $63 per share. assuming neither stock paid a dividend, which investment has the highest rate of return?

a.) stock a
b.) stock b
c.) bond
d.) stock a and stock b