peptides

I am trying to count charges and don't get this to add up. H,R,K each give +1, and D,E each give -1. Is there more to it than this? I thought option C resulted in +3 -3 = 0, but the solution says it is net -1.

Why is it that dipeptides and tripeptides can be absorbed in the intestinal wall but disaccharides have to be broken down to monosaccharides to be absorbed? Thank you!