choose android emulator

I use Sencha Cmd v5.0.2.270 and emulate an application with:

sencha app emulate native

I have tree emulators on AVD (different resolution), but I haven't figured out how to choose what the emulator start.

Using "sencha -d app emulate native", I see:

WARNING : no emulator specified, defaulting to XXXX

and I cannot choose, for example YYYY emulator

Anyone can help me?

choose android emulator