Which of the Following Statements Are True About Intermittent Positive-Pressure

Which of the following statements are true about intermittent positive-pressure breathing (IPPB) ?
1) IPPB could cause lung overinflation.
2) IPPB could cause no expansion of regions affected by secretions.
3) Bronchial hygiene must be used in conjunction with IPPB to adequately manage secretions.
4) IPPB should be the single treatment modality for gas absorption atelectasis.

A) 1 and 3 only
B) 1, 2, and 3 only
C) 3 and 4 only
D) 2, 3, and 4 only