Why Is 70% Ethanol Used to Sterilize Skin Before Injections

Multiple Choice

Why is 70% ethanol used to sterilize skin before injections instead of 95% ethanol?

A) 70% ethanol kills bacteria by denaturing their surface proteins.
B) 70% ethanol penetrates bacteria and kills them by coagulating their proteins.
C) 70% ethanol can kill bacteria without damaging their structures.
D) None of these are correct.