What is the basic structural and functional unit of all living organisms?

A. Increase fluid intake: While adequate hydration is important, it will not relieve acute urinary retention and may worsen discomfort if the bladder is already full.

B. Schedule an imaging study: Imaging may help identify the underlying cause but does not provide immediate relief of urinary retention, which is the priority.

C. Provide antibiotics and monitor for infection: Antibiotics are indicated only if infection is present; they do not address the acute obstruction causing retention.

D. Insert a Foley catheter: Inserting a Foley catheter immediately relieves bladder distension, prevents complications like hydronephrosis, and allows monitoring of urine output, making it the most urgent and effective intervention.

A. Alveoli: Alveoli are tiny sac-like structures in the lungs where oxygen and carbon dioxide are exchanged between the air and blood. Their thin walls and extensive capillary network maximize gas diffusion efficiency.

B. Pharynx: The pharynx serves as a passageway for both air and food. It does not participate in gas exchange but directs air toward the lower respiratory tract.

C. Trachea: The trachea conducts air between the larynx and bronchi. It provides a clear airway but is not involved in the actual exchange of gases.

D. Bronchi: Bronchi branch from the trachea to deliver air to each lung. They act as air passages and do not serve as the main site for gas exchange.