This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
A 40-year-old male presents with chronic diarrhoea for one year. On investigation, the findings obtained were crypt abscess, crypt atrophy, cryptitis and mucositis. Most likely diagnosis is - 
Select and explain. 
A. Crohn's disease, B. Ulcerative colitis, C. Microscopic colitis, D. Collagenous colitis
A: Crohn's disease
Answer: A: Crohn's disease 
Explanation: None