Which of the following APGAR criteria assesses muscle tone?

The correct answer is Activity, which evaluates the muscle tone of a newborn as part of the APGAR scoring system. The APGAR test is conducted at one and five minutes after birth to quickly assess the health of newborns based on five criteria: Appearance, Pulse, Activity, Grimace Response, and Respiration.

Specifically, Activity looks at the infant's movement and overall muscle tone. A score under this category reflects whether the baby exhibits normal muscle tone (active movements) or shows signs of decreased muscle tone (flaccidity).

While Appearance assesses skin color, providing insights on oxygenation and circulation, Pulse measures heart rate, indicating cardiovascular function. Grimace Response evaluates reflexes and responsiveness, and Respiration looks into the baby's breathing effort and rate. Although all these criteria are important for assessing a newborn's health, it is the Activity aspect that specifically focuses on muscle tone and movement.