An administrator decides to optimize WLAN performance by adjusting the fragmentation threshold on each access point to a value much lower than the default of 2346 bytes. She notices that when wireless client stations are doing prolonged data transfers from a wired server, that downstream performance is better than it was before her adjustments. One problem she has not yet solved is why performance in the upstream direction has not been improved due to these adjustments. As a wireless protocol analyst, which of the following explanations would you give to the administrator?

A.
Fragmentation thresholds settings are only effective in the downstream direction (toward the wireless client stations) as specified by the IEEE 802.11 standard.

B.
Fragmentation thresholds are uniquely set on each wireless client station and access point and affect only transmissions from that node in particular.

C.
When configuring fragmentation threshold values, it is important to enable RTS/CTS also in order to get effective bi-directional results.

D.
Fragmentation is only supported bi-directionally when Antenna Diversity is enabled on both wireless client stations and the access point.

E.
World Mode (also known as Multi-Domain Operation) must be enabled for fragmentation to be bi-directional due to regulatory requirements in most countries.