Proper Instructions for Positive Expiratory Pressure Include Which of the Following

Proper instructions for positive expiratory pressure include which of the following?
1) Take in a breath that is larger than normal, but do not fill lungs completely.
2) Exhale forcefully and maintain an expiratory pressure of 10 to 20 cm H₂O.
3) After 10 to 20 breaths, take two or three "huff"' coughs, and rest as needed.
4) Repeat the cycle 8 to 10 times, not to exceed 30 min.

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