Fill in the Missing Step in the Following Deadlock Situation

Multiple Choice

Fill in the missing step in the following deadlock situation.Two users from the local board of education are each running a program (P1 and P2) ,and both programs will eventually need two DVD drives to copy files from one disc to another.Only two DVD-R drives are available and they're allocated on an "as requested" basis.Soon the following sequence transpires:
1) P1 requests drive 1 and gets it.
2) ____
3) P1 requests drive 2 but is blocked.
4) P2 requests drive 1 but is blocked.

A) P1 requests drive 2.
B) P2 requests drive 2 and gets it.
C) P2 requests drive 1 but is blocked.
D) P1 releases drive 1.