Which statement about heart rate categories is true?

• A. Normal Sinus Rhythm refers to a heart rate between 60 and 100 bpm in adults.
• B. Sinus Tachycardia refers to a heart rate below 60 bpm.
• C. Sinus Bradycardia refers to a heart rate above 100 bpm.
• D. Normal Sinus Rhythm refers to a heart rate above 100 bpm.

Answer: (A)

Understanding heart-rate categories: Normal Sinus Rhythm means the resting heart rate is driven by the sinus node and falls between 60 and 100 beats per minute in adults. This range represents a typical, healthy adult at rest. Tachycardia is a rapid rhythm defined as more than 100 bpm, while bradycardia is a slow rhythm defined as less than 60 bpm. So, the statement that Normal Sinus Rhythm corresponds to a heart rate in the 60–100 bpm range is the correct one. The other options mix up the thresholds: tachycardia is not below 60; bradycardia is not above 100; and Normal Sinus Rhythm is not above 100 bpm.