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
Most common etiology of abnormal uterine bleeding in childhood age group 
Select and explain. 
A. Vulvovaginitis, B. Anovulation, C. Endometrial polyp, D. endometrial cancer
A: Vulvovaginitis
Answer: A: Vulvovaginitis 
Explanation: Vulvovaginitis is commonest etiology of AUB in childhood age group.