I completely agree! It's well established that the impact of (B) is substantial, I just wanted to make the (somewhat tangential) point that wealthier students'

I completely agree! It's well established that the impact of (B) is substantial, I just wanted to make the (somewhat tangential) point that wealthier students' empirical advantage at standardized tests is mostly not due to test prep, contrary to popular belief and to the GP comment's example.