Employees have Windows Mobile 6.5 devices. You manage the Windows Mobile devices by using Microsoft System Center Mobile Device Manager (MDM) 2008. Windows Mobile devices are required to use public key infrastructure (PKI) certificates when connecting to the corporate network through a VPN connection. You provision the Windows Mobile devices with the appropriate PKI certificates for the organization and the devices. You need to ensure that Windows Mobile devices use the PKI certificates when connecting to the corporate network through a VPN connection.
What are two possible ways to achieve this goal? (Each correct answer presents a complete solution. Choose two.)

A.
Use a PPTP VPN connection on the Windows Mobile devices.

B.
Use the MDM Remote VPN client on the Windows Mobile devices.

C.
Use an L2TP/IPSec VPN connection on the Windows Mobile devices.

D.
Use a VPN connection with a pre-shared key on the Windows Mobile devices.