In a sand mold casting, there are three mold cavities connected with each other, with TST (total solidification time) of (a) 1.5 mins (b) 2 mins (c) 3 mins respectively,

which one should be placed further from the riser than others? a) the one with TST=1.5 mins; b) the one with TST=2 mins; c) theone with TST=3 mins