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: Pharmacology
Indicate the drug which does not improve lower esophageal sphincter tone or prevent gastroesophageal reflux, but is used as the first line treatment of gastroesophageal reflux disease : 
Select and explain. 
A. Sodium alginate + aluminium hydroxide gel, B. Omeprazole, C. Mosapride, D. Metoclopramide
B: Omeprazole
Answer: B: Omeprazole 
Explanation: Increasing GI motility with prokinetic drugs (like metoclopramide and mosapride) or
By decreasing gastric acid secretion with PPIs like omeprazole.