This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cervical Carcinoma, Subject name: Gynaecology & Obstetrics
In Bethesda system, in 'LSIL' histologic changes are seen in: 
Select and explain. 
A. Basal One Third, B. Basal Half To Two Third, C. Whole thickness except superficial layers, D. Whole Thickness
A: Basal One Third
Answer: A: Basal One Third 
Explanation: CIN Bethesda System Description CIN I LSIL Dysplastic cells in lower 1/3 of cervix CIN II HSIL Dysplastic cells upto 2/3of cervix CIN III HSIL Dysplastic cells in > 2/3 of cervix Carcinoma in situ HSIL Dysplastic cells in full thickness but basement membrane is intact