The parents of a 4-week-old white boy bring their son to the pediatric emergency department concerned about their son’s feeding patterns. His mother reports he was feeding well for the first several...

The parents of a 4-week-old white boy bring their son to the pediatric emergency department concerned about their son’s feeding patterns. His mother reports he was feeding well for the first several days but developed nonbilious emesis toward the end of his second week of life. The episodes of emesis have worsened and now occur after every feeding, with some episodes being projectile in nature. Immediately after vomiting, the newborn is hungry and ready to feed again. He has a small, mobile nontender epigastric mass on physical examination. Heart rate is 128/min, blood pressure is 80/52 mm Hg, respiratory rate is 37/min, andtemperature is 37.5°C (99.5°F). What acidbase disorder is the patient most at risk of developing?

(A) Hyperchloremic-hypokalemic metabolic acidosis

(B) Hyperchloremic-hypokalemic metabolic alkalosis

(C) Hypochloremic-hyperkalemic metabolic alkalosis

(D) Hypochloremic-hypokalemic metabolic acidosis

(E) Hypochloremic-hypokalemic metabolic alkalosis