Explanation: The first step in checking for consciousness is to tap on the person or shake them and ask if they are okay. After you have determined that a person is not conscious is when you go to the next steps of checking the ABCs - airway, breathing and circulation.
((Well, some people say to place your ear over the persons mouth and watch for a rise and fall of the chest-- but that's not an answer nor does that really go with any of the answers provided so..))