Use the Following to Answer the Questions Below

Multiple Choice

Use the following to answer the questions below:
Consider taking random samples of size 100 from Population A with mean 85 and standard deviation of 15 and random samples of size 60 from Population B with mean 78 and standard deviation 12.
-Find the mean of the distribution of differences in sample means,

A) -7
B) 7
C) 78
D) 85