What Does the Supreme Court Say About Race and the Redistricting

What does the Supreme Court say about race and the redistricting process?

A) It cannot play any role in the redistricting process.
B) It must be the top priority in the redistricting process.
C) It may be a factor but may not be the predominant factor in the redistricting process.
D) It can only be used as a factor in the redistricting process in states in the South.
E) It should not be used in the computer models that draw district boundaries.