<p>...if they could change their subject tests at the test center. This is from collegeboard's website:</p>
<p>Test Change
You can change your test from SAT Reasoning Test to SAT Subject Tests or from SAT Subject Tests to SAT Reasoning Test. There is no charge for changing from one Subject Test to a different Subject Test. If you want to substitute one Subject Test for another, you should do that at the test center.</p>
<p>You may substitute any Subject Tests offered except the Language Tests with Listening. You cannot change to a listening test on test day because test centers do not have extra CDs. If you want to change to a listening test or from one listening test to another, you must do so by the late registration deadline.</p>
<p>Hope this helps!</p>