After Completing a Single-Breath Diffusing Capacity,which of the Following Comments

After completing a single-breath diffusing capacity,which of the following comments would assist with the interpretation process?

A) Four trials were completed after several false starts.
B) The VC was performed an hour before the DLCO.
C) The exhalation time was 2 seconds.
D) Was unable to achieve an IVC at 85% of the SVC.