What are the three starter Pokemon available in Pokemon Black and White?

The story behind the answer

Snivy, Tepig, and Oshawott are the three starters in Pokémon Black & White (Generation V), set in the Unova region. Professor Juniper offers this classic Grass–Fire–Water trio at the game’s start. The other options—Fennekin, Chespin, and Froakie—are from Generation VI’s Kalos region (Pokémon X/Y), so they don’t apply to Black & White.

Context and memory tip: Black & White introduced an all-new regional Pokédex and rivals (Cheren and Bianca) who reinforce the type triangle. Remember them by their names and animals: Snivy (“sn-ivy”) is a leafy serpent (Grass), Tepig is a hot-headed pig (Fire), and Oshawott is an otter with a shell that loves water (Water). Or use the acronym “STO” = Snivy–Tepig–Oshawott for Unova.