I don't understand why B is correct below. I thought the goal was find to consumer equilibrium where MUa/$ = MUb/$

And that mean you need 5 get larger and 8 to get smaller, thus buying more of A and less of b??

Ben is exhausting his money income consuming products A and B in such quantities that MUa/Pa = 5 and MUb/Pb = 8. Ben should purchase:

b. more of B and less of A.