I'm a junior chem major at UConn, and I'm looking to apply to grad school. I've just taken a few of my analytical chem tests, and I didn't fare well, because I struggled with the statistical formulas. Now it looks like I will probably get a C in the class. My GPA is 3.3 right now. Should I try to improve the grade by retaking the class, or does having a replaced grade on a transcript look bad?