"C" in AP science class for both semesters..how will this affect college admissions?

When S was in hs, his teacher indicated that there just wasn’t that much “precalc” material to learn and that she’d be through H Precalc material by Feb/Mar. At that point she’d move on to calc. If student thought they were grasping this material then they should consider AP Calc BC. If they were struggling then they should consider AP Calc AB.