What could cause this notebook computer to be performing poorly?

You recently installed an IEEE 802.11g wireless network in a small office. One of the employees has been complaining of poor performance and mentioned her notebook computer runs very slowly because of the access point it connects to.

What could cause this notebook computer to be performing poorly?
A . The new 5.8 GHz cordless telephone in her office is interfering with the IEEE 802.11g wireless LAN.
B . The access point is located at the opposite side of the building from the user’s office separated by several walls.
C . A media access control (MAC) filter is enabled on the notebook computer, causing excessive retries.
D . You recently rolled out a new version of the access point’s firmware to enable new features that became available.

Answer: B