Which of the Following Are Necessary to Ensure a Valid

Multiple Choice

Which of the following are necessary to ensure a valid single-breath diffusing capacity of the lungs (DLCO) test result?
I. Two or more acceptable tests should be averaged.
II. Breath-hold time should be between 3 and 5 seconds.
III. Corrections for hemoglobin (Hb) and COHb should be included.
IV. The maneuvers should be reproducible to within 10%.

A) I, II, and III
B) II and IV
C) I, III, and IV
D) I, II, III, and IV