CompTIA A+ 220-902 Question C-72

A user installed a new SOHO router and new wireless NICs to increase their transmission speed from 802.11b to 802.11g with the manufacturer’s default settings. The user lives in an apartment building and is still experiencing slowness to the Internet after the installations. Which of the following is the MOST secure option that a technician could implement to resolve this issue?

A. Hide the SSID
B. Assign static IP addresses
C. Enable MAC filtering
D. Disable the WAN port