I would say poison type, as normal type moves are not very effective, neither are fire attacks, and bug types are weak against rock. Therefore, I conclude that poison type, depending on your pokémon's attacks, you should go with your poison type pokémon.
ground type Pokemon are super effective against poison type Pokemon.
Psychic and ground type moves are super-effective against poison types I tried using fighting moves, and they were not very effective
Normal, fire, flying and poison type moves aren't really effective against rock type Pokémon.
Poison and Steel types are super effective against Fairy types.
Steel type Pokemon is super effective against: Ground, Fire, Fighting Steel type Pokemon are not effective against: Bug, Flying, Psychic, Ghost, Dark, Steel, Dragon, Grass, Normal, Ice, Rock. Steel type Pokemon are never effective by: Poison. Steel type Pokemon have a regular damage by (regular damage): Electric, Water. Hope this helps!
Poison is very effective against grass pokemon.
ground type Pokemon are super effective against poison type Pokemon.
ground and physic Pokemon are super effective against poison Pokemon
Ground and psychic type attacks are both super-effective against a poison type pokemon.
Psychic types are super effective against Poison types.
Ghost-type's resistances are Bug and Poison. They are completely immune to Fighting and Normal-types.
Psychic and ground type moves are super-effective against poison types I tried using fighting moves, and they were not very effective
Normal, fire, flying and poison type moves aren't really effective against rock type Pokémon.
use ghost type on her phsycic and phsycic on her poison Pokemon
In Generation 1 (Red, Blue, Yellow) Bug is super-effective against Poison, and Poison is super-effective against Bug. Weedle Kakuna Beedrill Venonat Venomoth
Fighting and Poison. It is not very effective on Steel, and has no effect on Dark.
Poison and Steel types are super effective against Fairy types.