A customer is reporting difficulty connecting some devices after replacing a wireless router with a new wireless 802.11ac router. The SSID, encryption and password are the same as the previous router. A technician goes on-site and notices the devices that are no longer connecting appear to be several years ago. Which of the following is MOST likely the problem?
A. the password needs to be re-entered.
B. there is a security type mismatch.
C. there is insufficient antenna power.
D. there is a frequency mismatch.
E. the channel has changed.