Final answer:
The redo of a knee replacement involving a new prosthesis is coded to the root operations 'removal' and 'replacement,' indicating the removal of the old device and insertion of a new one.
Step-by-step explanation:
The question "A complete redo of a knee replacement requiring a new prosthesis is coded to which root operation(s)?" is associated with medical coding, specifically the coding practices for surgical procedures. When a knee replacement prosthesis is completely removed and a new one is inserted, the correct coding would involve two root operations. The first root operation is removal, which refers to taking out or off a device from a body part, and the second root operation is replacement, which involves putting in or on biological or synthetic material that physically takes the place and function of all or a portion of a body part. Therefore, the correct answer is A) removal; replacement.