This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gastrointestinal System, Subject name: Physiology
The neurotransmitter at the vagal nerve ending on the G-cell is: 
Select and explain. 
A. Ach, B. Neurotensin, C. Bombesin, D. Entero-oxyntin
C: Bombesin
Answer: C: Bombesin 
Explanation: - G-cell in the pylorus secretes gastrin. - G-cell is innervated by vagal fibers; the transmitter of these fibers is bombesin, also known as gastrin-releasing peptide (GRP). - Neurotensin and entero-oxyntin are the peptides that influence the intestinal phase of the gastric acid secretion.