A technician connects a Cisco Aironet 3700 Series AP to a switch and realizes that the AP is coming up with 3x3 MIMO. What explains this behavior?

A technician connects a Cisco Aironet 3700 Series AP to a switch and realizes that the AP is coming up with 3x3 MIMO. What explains this behavior?

A. A redundant power supply is unavailable on the switch. B. The switch is 802.3af capable. C. The AP is getting power from a power injector. D. The switch is PoE+ capable.