Which of the following accurately describes a ruling the Supreme Court has been in an attempt to limit the practice of gerrymandering?

A. Congressional district lines will be redrawn every 20 years instead of every 10
B. Permanent district lines must be drawn in districts where the population has remained stable for at least 50 years
C. Gerrymandering based solely on racial data is illegal
D. Gerrymandering cannot be practiced in districts where representatives have served more than 5 consecutive terms