You are coupling a tractor to a semi-trailer. You have backed up but are not yet under it. Before backing under the semi-trailer, you should hook up
a) Nothing. Back up and lock the fifth wheel
b) The electrical service cable
c) The emergency and service air lines
Answer: c) The emergency and service air lines
If the answers is incorrect or not given, you can answer the above question in the comment box. If the answers is incorrect or not given, you can answer the above question in the comment box.