Senior year grades and college admissions

<p>How do the grades you earn senior year factor into the admissions process? I'm really worried that I will get a C in AP physics.. and this year I'm taking the hardest course load I have ever had. It looks as though by first semester most of my grades will be B's. Will this horribly ruin my chances at any good colleges?</p>

<p>Also, what about second semester grades? notoriously second semester is the time for seniors to slack and thus the grades drop a bit.. how low can they drop before a college chooses to let you go after admitting you?</p>

<p>If you're an A student, don't drop below B's.
If you're a B student, don't drop below C's.
If you're a C student, don't drop below D's.
If you're a D student, you're taking the wrong classes.</p>