There are two AP physics sequences:
- AP physics 1 and 2, no calculus
- AP physics C mechanics and E&M, with calculus
If he is not yet in calculus, that suggests that he is in AP physics 1 and can take AP physics 2 next year. If he takes calculus next year, he can choose AP physics C. Please clarify what AP physics courses are in question.
Since he already has all three of biology, chemistry, and physics, if he is not aiming for the most selective colleges, then there is probably some leeway in choosing a fourth science course (or even having a fourth science course at all) for college admissions.