This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Non communicable diseases, Subject name: Social & Preventive Medicine
Billings method is for - 
Select and explain. 
A. Screening, B. Contraception, C. Aboion, D. None
B: Contraception
Answer: B: Contraception 
Explanation: Cervical Mucus method Also known as 'Billing' s Method' or 'Ovulation method' Based on changes in characteristics of cervical mucosa 1.At ovulation : Watery, clear, smooth, slippery, profuse (like egg White) 2. After ovulation : Thickens and lessens in quantity Ref: Park 25th edition Pgno : 559