This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diabetes, Subject name: Pathology
A 14-year-old boy presents for a pre-summer camp physical examination. Routine urinalysis discloses 3+ glucosuria. He admits to thirst and frequent urination, accompanied by a 4-kg (9-lb) weight loss over past few months. His parents note that he had a flu-like illness 5 months ago. His blood glucose is 220 mg/dL. Which of the following best explains the pathogenesis of hyperglycemia in this patient? 
Select and explain. 
A. Excess dietary glucose, B. Increased peripheral insulin uptake, C. Irregular insulin secretion, D. Islet cell destruction
D: Islet cell destruction
Answer: D: Islet cell destruction 
Explanation: Type 1 diabetes mellitus (T1DM) -Lifelong disorder of glucose homeostasis that results from autoimmune destruction of b-cells in islets of Langerhans. - Clinical onset coincides with another acute illness, such as febrile viral or bacterial infection. - Characterized by low or absent insulin secretion. - Most characteristic early finding in pancreas is lymphocytic infiltration in islets (insulitis), - As disease becomes chronic, b-cells of islets are progressively depleted.