<p>Make a spreadsheet of the schools you want to apply to and determine which schools need which subject tests. If you want to apply to one that needs a physical science SAT II, then you’d better take Chemistry. It’s your only option. Basically, if you don’t meet the testing requirements for having a complete application, then you shouldn’t apply. </p>
<p>There are plenty of great schools that don’t require subject tests at all, so the choice is yours. </p>