I wouldn’t waste time with this. It will look a lot better to take higher level courses and do well with them later rather than to waste your time taking general chemistry again.
I don’t agree with this advice either. A 3.75 GPA is good enough that it won’t be disqualifying for essentially any graduate program, and you can still certainly still get into a lot of great programs with lower GPAs (e.g. I got into a “top 10” engineering PhD program with a 3.4 undergraduate GPA).
This right here is solid advice. It’s really a pretty qualitative process when it comes to graduate school admissions.