At the start of 2020 you purchase 100 shares of a stock for the market price of $12 per share. At the start of 2021 the stock is worth $15 per share. Sometime during the summer of 2021 the stock has a 3:1 split. At the start of 2022 you sell all your shares for the market price of $8 per share. What is your arithmetic average return per year?

A) 25%

B) 42.5%

C) 50%

D) 85%

E) 100%