A 6 \mathrm{~m} by 8 \mathrm{~m} rectangular field has a fence around it. There is a post at each of the four corners of the field. Starting at each corner, there is a post every 2 \mathrm{~m} along each side of the fence. How many posts are there?
Answer Choices
A. 12
B. 14
C. 16
D. 18
E. 20