Differential smears categorize types of white cells in a sample.

During a frontal collision, MOST pneumothoraces occur when:

A) the patient takes a deep breath just before impact and the lungs rapidly decompress at the time of impact. B) the diaphragm rapidly ascends into the chest cavity during impact, causing an increase in intrathoracic pressure. C) the chest strikes the steering wheel, which fractures one or more ribs and causes a perforation injury to one of the lungs. D) the patient is ejected through the windshield, and his or her chest collides with a secondary object outside the vehicle.

When using pulse oximetry long-term, you should move the sensor to a new site every ____. 

A. 4 hours B. 2 hours C. 6 hours D. 12 hours E. 24 hours