Henry divided his socks into five groups. Let s represent the total number of socks. Which expression and solution represent the number of socks in each group if s=20?
A. S/5; when s=20, the number of socks in each group is 4.
B. S/5; when s=20, the number of socks in each group is 15.
C. S-5; when s=20, the number of socks in each group is 4.
D. s-5; when s=20, the number of socks in each group is 15.