Eight digits from 1 to 8 are divided into two groups. It is known that the sum of the digits in the first group equals the sum of the digits in the second group, and the number of digits in each group equals one of the digits in that group.
Accordingly, which of the following digits is in the same group as digit 7?
A) 2
B) 3
C) 4
D) 5
E) 6