((The answer to the first pokemon is Bulbasaur. He’s #1 in the Pokedex)) Humans are probs Mew lol
Technically, they’re all the right answer; the question is just phrased vaguely enough that it’s not clear which one it should be.
Bulbasaur is #001 in the National ‘Dex, and thus is the first in the Pokedex.
Mew is basically described as being the Last Universal Common Ancestor of all Pokemon, which would make it the “first” Pokemon. It was also the first Pokemon to be copyrighted.
However, Rhydon was the first Pokemon to be designed, and its index number in the Gen I games was 001.
And numerous Pokedex entries refer to Arceus as being the first thing to come into existence and being the creator of the Pokemon world.
So they’re all technically the “first”… just the first of different things, and the question doesn’t specify which thing it’s talking about.