This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Scabies and other infestations, Subject name: Dental
Drug of choice in scabies in pregnant woman is - 
Select and explain. 
A. Permethrin, B. Gamma Benzene Hexachloride, C. Ivermectin, D. Benzyl benzoate
A: Permethrin
Answer: A: Permethrin 
Explanation: Topical Permethrin 5% lotion is DOC in scabies in pregnant woman. MOA of Permethrin: Acts on Na channels. Crotamiton 10% and Precipitated sulphur can also be used Gamma Benzene Hexachloride: C/I in pregnancy. Ivermectin: Systemic agent used only in most severe scabies. Benzyl benzoate: disadvantage is multiple application is required.