The correct answer is A) cool adjoining horizontal and vertical surfaces before opening the galley door. The reasoning for this is that when dealing with a class "A" fire (a fire involving ordinary combustible materials like wood, paper, or fabrics), it is important to first cool the surrounding surfaces before opening the door. This helps prevent the fire from rapidly spreading once the door is opened. Opening the door without first cooling the surfaces could allow the fire to flare up and potentially cause injury to the firefighters. The other options are incorrect because they do not properly address the need to cool the surrounding surfaces before attempting to extinguish the fire.