Biochemistry - Gel Electrophoresis - Discussion

Thanks @Mohammad.

SDS is an ionic detergent which imparts the negative charge to denatured proteins, generally, one SDS molecule binds with two amino acids hence all proteins in the sample have a negative charge so that the protein in the gel will migrate on the basis of charge to mass ratio. The proteins having less molecular weight will migrate faster in the gel as compare to the proteins having the higher mass to charge ratio.

All of the above as (d) option is correct, SDS is used as denaturing and in this protein are separated on the basis of charge and weight.