The following separation technique depends on the molecular size of protein:

Ans. is 'c' ie., Gel filtration chromatography These are different techniques of purification of proteins. They take advantage of one or other property of protein for their separationOption (a) and (d)Chromatography on carboxymethyl cellulose column or diethyl aminomethyl cellulose column separate protein depending on the net electric charge of the proteinsOption (b)Isoelectric focusing separates proteins according to their isoelectric pointsOption (c)Gel filtration chromatography separates protein according to their molecular sizesLehninger states - "Gel filtration column matrix is a cross-linked polymer with pores of selected size. larger proteins migrate faster than smaller ones because they are too large to enter the pores in the beads and hence take a more direct route through the column. The smaller proteins enters the pores and are slowed by the more labyrinthine path they take through the column"