题目内容:
A.TherearenoinstancedofAthatwillbecomeeligibleforgarbagecollection.B.ExplicitlysettingmyAtonullmarksthatinstancetobeeligibleforgarbagecollection.
C.AnycallontryIt()causestheprivateinstanceofAtobemarkedforgarbagecollection.
D.PrivateinstancesofAbecomeeligibleforgarbagecollectionwheninstancesofAlphabecomeeligibleforgarbagecollection.
参考答案: