Why Did Radical Republicans Want to Disenfranchise Former Confederates

Why did Radical Republicans want to disenfranchise former Confederates?

A) To make the South a northern colony
B) To ensure the South would never rejoin the Union
C) To keep former Confederates from electing Democrats eager to restore the old southern ruling class to power
D) To facilitate a complete national reconciliation that included both southern whites and blacks
E) To anger President Lincoln