Answer: B. He should buy fewer pears and more oranges
Step-by-step explanation:
Harold receives more marginal utility per dollar from oranges than from pears which simply means that he derives more pleasure from buying oranges than from buying pears.
To maximise his utility therefore, Harold should buy more of the good that gives him more satisfaction which in this case are oranges and buy less of the one that gives him less satisfaction which are pears.