For, you know, major majors, I'd say economics,
because the terms can all be defined in so many
ways,
and everything's so vague, that you can
just not
recognize something from a definition
that someone took
straight from a textbook.
To take your question
literally (ANY major), I
looked at Pitt's list of
majors and I'd probably
go with Teaching English as a
Second Language or
Polish.