<p>They look at both.
Also, quote from [Caltech</a> Undergrad Admission FAQ](<a href=“http://www.admissions.caltech.edu/faqs]Caltech”>http://www.admissions.caltech.edu/faqs):
</p>
<p>You should strive for more difficult APs in math/science.
Might be helpful to look at stats of people from last year: <a href=“http://talk.collegeconfidential.com/california-institute-technology/824654-consolidated-ea-rd-2014-results-thread.html[/url]”>http://talk.collegeconfidential.com/california-institute-technology/824654-consolidated-ea-rd-2014-results-thread.html</a></p>
<p>Last thing… don’t make CalTech a “not getting in is not an option”. Chances are, even for an extremely qualified student, it’s still a stretch.</p>