subgingival calculus

9. Patient H’s teeth have a lot of subgingival calculus that should be removed. Dr. Jackson usually prefers to use the ultrasonic scaler for subgingival scaling, but the patient has a poorly shielded cardiac pacemaker. Which of the following instruments would be the most appropriate instrument to use on this particular patient?
A. File
B. Probe
C. Curette
D. Portepolisher