A campus infrastructure supports wireless clients via Cisco Aironet AG Series 1230， 1240， and 1250 access points. With DNS and DHCP configured， the 1230 and 1240 access points appear to boot and operate normally； however， the 1250 access points do not seem to operate correctly.  What is the most likely issue causing this problem？（）

• A、PoE
• B、DHCP with option 150
• C、DHCP with option 43
• D、DNS
• E、switch port does not support gigabit speeds