This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: NEET Jan 2020, Subject name: Surgery
Patient presents with peritonitis and during surgery a diveicular perforation is seen with fecal peritonitis. What is the Hinchey's stages? 
Select and explain. 
A. 1, B. 2, C. 3, D. 4
D: 4
Answer: D: 4 
Explanation: Hinchey classification of complicated diveiculitis. GRADE Grade I Mesenteric or pericolic abscess Grade II Pelvic abscess Grade III Purulent peritonitis Grade IV Faecal peritonitis