What is the best method to decrease duty cycle (radio frequency utilization) and increase overall wireless LAN client performance for this design?

You are designing a wireless LAN with the following components:

. High-density indoor access point deployment

. 2.4-GHz and 5-GHz radios

. 802.11a, 802.11g, and 802.11n mode wireless LAN clients

Site survey results show negligible foreign WiFi and non-WiFi interference.

What is the best method to decrease duty cycle (radio frequency utilization) and increase overall wireless LAN client performance for this design?
A . Disable all data rates below 12 Mb/s on all access points.
B . Decrease radio transmit power on all access points that report a high duty cycle.
C . Increase radio transmit power on all access points that report a high duty cycle.
D . Disable all data rates above 12 Mb/s on all access points.
E . Increase radio transmit power on all access points.