>>51088944Pokémon is short for Pocket Monster, meaning the question is asking about the very first monster that was caught in a pocket-sized contraption.
Can’t be Bulbasaur since Oak had relatively recently just decided to record Pokemon. Can’t be Mew, since other pokemon were caught before it, same applies to Arceus. Perhaps it’s Rhydon, since it was the very first pocket monster drafted, therefore it is safe to assume it is the very first monster to be caught and tamed by humans.