I know the answer is A, but I my calculations isn't correct

Tonya purchased 500 shares of Home Depot, Inc., common stock on December 13, 2016, at a cost of $3,600. She paid a commission of $150 on the purchase. On February 18, 2020, she received 250 shares of Home Depot, Inc., common stock as a tax-free dividend. Tonya sold 600 shares for $3,700 on January 8, 2021, and paid a $100 commission on the sale. Tonya's gain (or loss) on the sale is characterized as a:

a. long-term capital gain of $600.

b. long-term capital gain of $500 and a short-term capital gain of $100.

c. long-term capital loss of $50.

d. short-term capital gain of $600.