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: Gynaecology & Obstetrics
Half life biological of oxytocin: 
Select and explain. 
A. 2-3 min, B. 3-4 min, C. 5-6 min, D. 7-8 min
B: 3-4 min
Answer: B: 3-4 min 
Explanation: Oxytocin

It is a nonapeptide (Peptide of nine amino acids).
Released by posterior pituitary and synthesized in the supra optic and paraventricular nucleus of hypothalamus.
Half life 3–4 minutes.
Duration of action – 20 minutes.
Mechanism of action – Acts through calcium mediated channels to initiate myometrial contractions.