The correct answer is A) emergency treatment at the scene of the injury. First aid refers to the immediate, basic care provided to a person who has been injured or is experiencing a sudden illness, typically at the location where the incident occurred. The goal of first aid is to stabilize the individual's condition and prevent the situation from worsening until more advanced medical treatment can be administered. The other answer choices are incorrect because they do not accurately reflect the definition of first aid. B) dosage of medications and C) medical treatment of accident are more aligned with the responsibilities of trained medical professionals, not first aid providers. D) setting of broken bones is a specific type of medical intervention that goes beyond the basic, immediate care provided through first aid.