<p>One C isn't going to kill you, although you should work hard to keep the others up. And don't worry that Stanford will just kick you out, rescinding an admission is a big deal and they would definitely give you a chance to explain.</p>
<p>Also, what class is it in? That might make a difference.</p>
<p>I don't think one C is going to make a difference at all. Like zeller said, revoking admissions a big deal, and one C is going to look like an anomaly, not a pattern. Maybe if you had mostly B's and a C it would make a difference.</p>