This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Surgery
A 35-year-old male who had a chronic duodenal ulcer for the last six years presents with worsening of symptoms, loss of periodicity of symptoms, pain on rising in the morning, sense of epigastric bloating and post-prandial vomiting. The most likely cause of the worsening of his symptoms is development of 
Select and explain. 
A. Posterior penetration, B. Gastric outlet obstruction, C. Carcinoma, D. Pancreatitis
B: Gastric outlet obstruction
Answer: B: Gastric outlet obstruction 
Explanation: Chronic duodenal ulcer after many years undergoes scarring and cicatrisation causing total obstruction of the pylorus. Reference: SRB edition:5 page no. 828