<p>I wouldn’t worry about what to take senior year if the student finishes BC Calculus as a junior. High schools usually have lots of interesting elective choices for seniors. They may not necessarily be math courses, but this doesn’t matter much. </p>
<p>In the high school my daughter came from, quite a lot of people took BC Calculus as juniors. Some then took multivariable calculus or AP Statistics as seniors, but others chose to take an extra elective in some other academic area – such as an additional AP social studies or science course. This didn’t seem to harm their college admissions prospects.</p>
<p>Of course, it’s important to find out whether the high school requires four years of math taken in high school for graduation. This one did not. It required four years of high school level math, and algebra and geometry taken in middle school counted toward the total.</p>