The partner options are the cast of player/partner monsters (but it has some restrictions, like no duplicate element, unless you turned that off in the settings first). Speaking of, you can disable the Personality Quiz in the settings and pick any of the choices available to answer your question >vv<
The player/partner monsters are: Barioth, Barroth, Espinas, Farunokku, Great Maccao, Lagiacrus, Lagombi, Legiana, Magnamalo, Malfestio, Mizutsune, Nargacuga, Odogaron, Paolumu, Pukei-Pukei, Rathalos, Rathian, Tobi-Kadachi, Yian Kut-Ku, and Zinogre