I'm a Sophmore in hs, im in french 3 and i have a 79%, but all of my other grades are A's.

Last year my gpa was a 4.4 with no pass failed classes. I would like to attend a very selective school, so i was wondering. What would look worse: A pass fail of a world langauge, or a low b or a c?

The pass/fail is better. You get credit for the class and you don’t have the gpa dip.

Will colleges frown upon it?

I think you should take all HS core classes for a grade. I would seek out extra help in French and work hard to keep the grade in the B range.