15. Melon Company granted 180,000 restricted stock awards of its no par common shares to executives, subject to forfeiture if employment is terminated within three years. Melon's common shares have a market price of $10 per share on January 1, 2017, the grant date, and at December 31, 2018, averaging $10 throughout the year. When calculating diluted EPS at December 31, 2018, the net increase in the denominator of the EPS fraction will be _______ shares.

A. 180,000

B. 0

C. 120,000

D. 60,000