A. If only one thread is blocked in the wait method of an object， and another thread executes the modify on that same object， then the first thread immediately resumes execution.
B. If a thread is blocked in the wait method of an object， and another thread executes the notify method on the same object， it is still possible that the first thread might never resume execution.
C. If a thread is blocked in the wait method of an object， and another thread executes the notify method on the same object， then the first thread definitely resumes execution as a direct and sole  consequence of the notify call.
D. If two threads are blocked in the wait method of one object， and another thread executes the notify method on the same object， then the first thread that executed the wait call first definitely resumes execution as a direct and sole consequence of the notify call.