An 11-month-old infant is admitted with a possible diagnosis of pyloric stenosis.

(A) There is no evidence of pain in infants with pyloric stenosis whether eating or not. (B) There are both good appetite and feeding habits in these children. (C) Because of regurgitation, there is usually decreased frequency and quantity of stools and also signs of dehydration and weight loss. (D) Along with upper abdominal distention, there is a characteristic palpable olive-shaped mass located to the right of the umbilicus.