Calculus AB or Calculus BC

My D is in 11th grade. Takes Calculus BC. Last semester she got B+ and this is the only B that she has. Next semester will be more difficult because 1)Calculus gets more difficult 2) she will take additional classes 3) She will prepare for AP exams 4) she will participate in Track team competitions.

I suggest her to switch to Calculus AB for the next semester. It will make her load much more manageable. She is NOT a STEM girl and NOT planning to apply for STEM major.

What do you think? What is better, get a couple of Bs or switch to an easier class in the middle of the year? What looks better for college admission?