Refer to the exhibit.

The HQ site uses area code 650. The BR1 site uses area code 408. The long distance national code for
PSTN dialing is 1. To make a long distance national call, an HQ or BR1 user dials access code 9,
followed by 1, and then the 10-digit number. Both sites use MGCP gateways. AAR must use
globalized call routing using a single route pattern. Assume that all outgoing PSTN numbers are
localized at the egress gateway as shown in the exhibit.
What should the AAR group prefix be?

A.
9

B.
91

C.
none

D.
+

E.
+1