Which of the following is a sign of hypoglycemia?

Hypoglycemia, or low blood sugar, typically manifests with a range of symptoms due to the body's response to a lack of glucose, which is a primary energy source for the brain and other organs. The presence of irritability and confusion in option C aligns well with common signs of hypoglycemia. When blood sugar levels drop, individuals often experience changes in mood, difficulty concentrating, and an overall sense of discomfort—examples being irritability and confusion.

In contrast, while seizures and coma can indeed result from severe hypoglycemia, they are usually signs of a more advanced and critical state rather than early warning signs. Bradypnea and chest pain are more indicative of respiratory or cardiac issues rather than hypoglycemia. Lastly, although increased heart rate can occur during hypoglycemia as part of the body’s fight-or-flight response, abdominal pain is not a typical symptom associated with low blood sugar levels. Hence, the characteristics of being skinny, irritable, and confused specifically highlight the neuroglycopenic effects of hypoglycemia, making this choice the most accurate representation of its signs.