My kid took the easy A Freshman year in math. As a Freshman, tested out of the second year math program but wanted to make sure that they knew the entire foundation. So took it anyway. This year math is still pretty easy. It’s not a bad thing. My kid knows they will not go into pure math. Reaching BC Calc plus one is enough in high school( and kiddo realizes that it will get increasingly more difficult in Years 3& 4). If your kid is a math kid, then I would advocate. But you should know the path your kid is on. Can they reach the math they are likely to need for their career? If not, then speak to the Dean. Getting 100 indicates mastery.
I’m surprised the teacher isn’t asking your kid to solve the problem in a couple of ways or using your kid to explain deeper contexts. Last year, the math teacher did this so my kid wasn’t bored. Often math teachers have also given my kids really tough conceptual problems to teach the same thing. Math kids love challenges.