Study the following bar graph and answer the question given below.
The bar graph represents the total number of applications received for B.Sc. Mathematics by two different colleges A and B in 5 different years.

Find the difference between the average number of applications received by college A from 2014 to 2018 and the average number of applications received by college B from 2014 to 2018?

A

5

B

4

C

6

D

8