Which of the following is a sign of respiratory acidosis?

Respiratory acidosis occurs when there is an accumulation of carbon dioxide in the body, leading to a decrease in blood pH. A key sign of respiratory acidosis is central nervous system (CNS) depression. This occurs because an increase in carbon dioxide can result in sedation of the CNS, which manifests as confusion, lethargy, and reduced responsiveness.

As the condition progresses, the increased carbon dioxide levels can impair brain function, leading to symptoms such as drowsiness and decreased mental alertness. Therefore, observing CNS depression indicates that the body is responding to higher levels of CO2 and a shift in the acid-base balance due to respiratory issues.

The other options, while they might be associated with respiratory conditions, do not specifically correlate as direct signs of respiratory acidosis. Hypotension can occur in various clinical scenarios but is not a definitive sign of respiratory acidosis. Fever typically suggests an infectious process rather than a direct disturbance of acid-base balance. Audible wheezing may indicate airway obstruction or reactive airway disease, but it doesn't indicate the underlying condition of respiratory acidosis itself.