what is the minimum version of Cisco CallManager that you should have?

For a Media Gateway Control Protocol (MGCP) gateway to register, what is the minimum version
of Cisco CallManager that you should have?

A.
3.0(1)a

B.
3.0(2)a

C.
3.0(3)a

D.
3.0(4)a

E.
3.0(5)a

F.
3.0(6)a