The correct answer is Option D: Diabetic ketoacidosis.
Diabetic ketoacidosis (DKA) is a serious condition that occurs in individuals with diabetes, particularly type 1 diabetes, and is characterized by severe hyperglycemia, ketone production, and metabolic acidosis. While diabetes mellitus (Option B) is a broad category that includes various types of diabetes, DKA specifically refers to a severe condition associated with hyperglycemia.