Which step can be taken to ensure that only FortiAP devices receive IP addresses from a DHCP server

Which step can be taken to ensure that only FortiAP devices receive IP addresses from a DHCP server on FortiGate?

A. Change the interface addressing mode to FortiAP devices.
B. Create a reservation list in the DHCP server settings.

C. Configure a VCI string value of FortiAP in the DHCP server settings.

D. Use DHCP option 138 to assign IPs to FortiAP devices.