A student used the SDS-PAGE method to estimate the size of a protein. Through gel filtration the molecular weight of the protein was 400 daltons. However, when he did SDS-PAGE he saw 3 different lines at A (25 daltons), B (50 daltons) and at C (75 daltons). What is the total composition of the protein, including each subunits molecular weight?

A. 2 of subunit A, 4 of subunit B, and 2 of subunit C
B. 6 of subunit B, and 4 of subunit A
C. 8 of subunit A, 1 of subunit B, and 2 of subunit C