ANS:D - Objects that can be reached from a live thread will never be garbage collected.

Option D is correct. Option C is wrong. See the note above on Islands of Isolation (An object is eligible for garbage collection when no live thread can access it - even though there might be references to it). Option B is wrong. "Never again be used" does not mean that there are no more references to the object. Option A is wrong. Even though Java applications can run out of memory there another answer supplied that is more right.