In a WLAN network, the working status of the AP will be affected by the surrounding environment. To avoid signal interference, it is recommended that adjacent APs work on non-heavy channels. The…

In a WLAN network, the working status of the AP will be affected by the surrounding environment. To avoid signal interference, it is recommended that adjacent APs work on non-heavy channels. The following figure shows different channel planning methods for four APs. Which of the following options are in line with the channel planning principles and have the least interference between APs? (Multiple choice)