A large, protruding tongue on an infant can be a sign of:

Rationale: A. Congenital hypothyroidism often presents with features such as a large, protruding tongue, poor feeding, lethargy, and hypotonia. B. Hypoparathyroidism typically presents with hypocalcemia-related symptoms like tetany, seizures, or muscle cramps, not a large tongue. C. Hyperparathyroidism is rare in infants and more likely to present with symptoms related to high calcium levels such as vomiting, constipation, or lethargy. D. Hyperthyroidism usually causes increased metabolism, irritability, weight loss, and tachycardia — not a protruding tongue.