If 15 subjects take a pre-test and a post-test with a mean change score of 1.5, and if the standard deviation of the comparison distribution is calculated to be .5, what is the t score?
A. 1.5/(15-1)=0.11
B. 1.5/15=0.10
C. 1.5/.5=3.00
D. 1.5/(.5(15-1)=0.21