Which statement describes what occurs during an inter-MME tracking area update
procedure?

A.
The old MME does the integrity check of the context request by using the old GUTI in the
context request message.

B.
The SGW change indication is conveyed to the old MME in the context ack message.

C.
The SGW change indication is conveyed to the old MME in the context request message.

D.
The old MME does the integrity check of the context request by using the PTMSI
signature in the context request message.

Explanation: