Which of the following is a sign of respiratory distress?

Hyperventilation is a sign of respiratory distress because it indicates that a person is attempting to compensate for inadequate oxygen supply or excess carbon dioxide in the body. During respiratory distress, the body's demand for oxygen increases and may trigger rapid and deep breathing to enhance ventilation. This hyperventilation response can occur in various conditions such as asthma exacerbations, panic attacks, or pulmonary infections, where the respiratory system is compromised.

Understanding the context of the other options helps clarify why hyperventilation is the most appropriate choice. Bradycardia, which is a slower than normal heart rate, typically suggests issues like excessive vagal stimulation or insufficient oxygenation but does not directly indicate respiratory distress. Decreased urination is often a sign of dehydration or kidney dysfunction rather than a direct response to respiratory issues. Hypertension, while it can be seen in various stressful situations, is not a specific indicator of respiratory distress and is often influenced by other factors such as pain, anxiety, or underlying cardiovascular issues. Thus, hyperventilation stands out clearly as a direct response to conditions causing respiratory distress.