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
Use of progestin only pill as a mode of contraception is contraindicated in all of the following conditions, EXCEPT: 
Select and explain. 
A. Lactation, B. Liver tumors, C. Acute liver disease, D. Known breast cancer
A: Lactation
Answer: A: Lactation 
Explanation: Progestin only pill is an excellent choice of contraception in lactating women. In combination with lactation, it is viually 100-percent effective for up to 6 months and does not impair milk production. Progestin only pill causes alterations in cervical mucus and on the endometrium, they do not reliably inhibit ovulation. Use of progestin only pill is contraindicated in women with: Breast cancer Acute liver disease Unexplained uterine bleeding Benign or malignant liver tumor Ref: Cunningham F.G., Leveno K.J., Bloom S.L., Hauth J.C., Rouse D.J., Spong C.Y. (2010). Chapter 32. Contraception.