what is the answer to this
What happens to the mean of the data set
{2, 4, 5, 6, 8, 2, 5, 6} if the number 7 is added to the data set?

A. The mean decreases by 1.
B. The mean increases by 2.
C. The mean increases by 0.25.
D. The mean increases by 0.75
im going nuts!!!!!!