Quick Diluted EPS question 2004, its, different, explained, following

studyn

Empire Watch Companys basic earnings per share (EPS) and diluted earnings per share (Diluted EPS) were both $2.00 in 2004, in 2005 basic EPS was $2.50 but Diluted EPS was $2.25. The fact that basic EPS and diluted EPS were the same in 2004 and different in 2005 could possibly be explained by any of the following EXCEPT:
A) the average price per share of Empire Watch’s common stock was higher in 2005.
D) Empire Watch purchased its own stock and held it as treasury stock in 2005.
I took out B and D bc they were obviously not it (convertible shares).
It’s D, but can someone explain the mechanics of A?