Hello, can someone please explain to me how they got the answer to the below question?

The following information is available for Barone Corporation:

January 1, 2015 Shares outstanding 2,000

April 1, 2015 Shares issued 320,000

July 1, 2015 Treasury shares purchased 120,000

October 1, 2015 Shares issued in a 100% stock dividend 2,200

The number of shares to be used in computing earnings per common share for 2015 is

a. 4,520,800.

b. 4,380,000.

c. 4,360,000.

d. 2,730,000.

[(2,000,000 3 2) + (2,320,000 3 2) + (2,200,000 3 2)

+ (4,400,000 3)] 12 = 4,360,000