__________(1)wrote，“Friendships are，from year to year，the best of all life's treasures.”But__________(2)a good friend to someone is never simple or easy.It__________(3)wisdom and lots of hard work.Demanding that a friend give his full attention__________(4)you can destroy a relationship.Let your friend decide for himself __________(5)to spend time with.

5. （）

A.what
B.person
C.which
D.whom