Earlier quoted context omitted.
Some schools which allow students to take calculus 1 and 2 before senior year also offer multivariate calculus (3), differential equations, and linear algebra courses to round out the fourth year of math. This is especially prevalent when students can take geometry in 8th grade which leads to Algebra II, Pre-Cal, Calculus, Advanced Math Electives as the four year progression.
My public high school in TX had that track. Is this uncommon in California schools? (I think the idea that it's in any means required to be able to do STEM in college is ludicrous, but having the option is great.)
I took Advanced Calc and AP Stats senior year, which in retrospect was a mistake :P