The following information pertains to J Company's outstanding stock for 2021:

Common stock, $1 par
Shares outstanding, 1/1/2021 10,000
2 for 1 stock split, 4/1/2021 10,000
Shares issued, 7/1/2021 5,000

Preferred stock, $100 par, 7% cumulative
Shares outstanding, 1/1/2021 4,000

What is the number of shares J should use to calculate 2018 basic earnings per share?

a. 20,000.
b. 22,500.
c. 25,000 .
d. 27,000.