A group of 11 athletes was compared to another group of 16 non-athletes with respect to Grade Point Average. The sample data are given below.

Athletes: Mean = 2.2, s1 = 1.5, n1 = 11
Non-Athletes: Mean=2.2, s2=1.0, n2=16
a. 2
b. 18
с. 10
d. 0