Which of the following statement regarding the physical principles governing humidifiers is correct?

Correct Answer: B

Rationale: Greater surface area increases the contact between gas and water, enhancing evaporation, which is a fundamental principle of humidifier function.

Correct Answer: A

Rationale: The diaphragm is the primary muscle of inhalation, contracting to expand the thoracic cavity.

Correct Answer: A

Rationale: Increased mucus production is a hallmark of COPD exacerbation, while domed diaphragms (chronic) and vesicular sounds (normal) are not specific to exacerbations.

Correct Answer: D

Rationale: Pulse pressure is the difference between systolic and diastolic pressures, reflecting arterial stiffness and stroke volume.

Correct Answer: D

Rationale: A small roll under the shoulders aligns the newborn's airway (sniffing position) for effective bag-mask ventilation.