Default radio mode nrf52840 with OpenThread SDK.

Hi there, I'm using nrf52840 with OpenThread SDK and I wanna know, what is default radio mode of this device? Because we also have another project with Bluetooth and we observe some interference. I assume that with OpenThread SDK device need to use the 802.15.4 radio mode, isn't? In the pic below, I don't see what mode is the default.

Thanks!