Which does not belong?

[Momiji]

Let's play a game!

Name three to five things of general knowledge, with one that does not belong. And whoever guesses must say what does not belong, as well as why it does not belong. You can make these as tricky as you want, but it still must remain in general knowledge-- there's no point in asking when it's something so obscure that no one will know the answer.

Example:
Red, yellow, blue, green

Answer: Green
Explanation: Red, yellow, and blue are primary colors, green is not.

I'm not exactly sure how this can be a 'one post in ten' deal, so please keep unnecessary posts to a minimum.

I'll start off with a simple three-choice one:

Soybean, Peanut, Almond.

Which does not belong, and why?