This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General obstetrics, Subject name: Anatomy
Uterine contractions are clinically palpable when there intensity is more than? 
Select and explain. 
A. 10mmHg, B. 15mm Hg, C. 20mmHg, D. 40mm Hg
A: 10mmHg
Answer: A: 10mmHg 
Explanation: Uterine contractions are palpable when intensity exceeds 10 mmHg Uterine contractions become painful when intensity exceeds 15 mmHg Intrauterine pressure at which uterus becomes hard that it cannot be indented by figure -40 mmHg. Ref: Williams Obs 24e pg 498.