Predicted grades

Im currently predicted an A* in welsh bacc, an A in psychology and a B in both biology and chemsitry and Im looking to apply to pharamcy. I am eligible for an alternative offer which is an A in welsh bacc and a B in chemistry and a B in a second science (biology or psychology). Although I meet the offer i was wondering if i should retake a biology paper to increase my predicted to an A as I got a B on one paper and a D on another paper which brought my grade down to a C but I've been predicted a B. I'm worried since pharamcy is a competitive course and Im worried my A in pscyhology won't be weighted the same as if someone who got an A in biology. I am also already retaking a chemistry paper so I am unsure if I should or if I have a chance to get an offer.