A Patient Diagnosed with Active Tuberculosis Is in a Negative

A patient diagnosed with active tuberculosis is in a negative pressure room for respiratory airborne isolation. How long should the nurse maintain the patient in this type of isolation?

A) until sputum specimens for acid-fast bacilli are negative
B) until the Mantoux test (PPD) converts from positive to negative
C) until the patient has orders for discharge
D) until the chest x-ray is normal