that is if a single fuel tank is installed. if you have multiple tanks with different types of fuel in each tank then they need consideration also. Each tank will need its own classification area and if you have overlapping areas you need to wire for the higher classification if you are in that area.
if its class I you have to use a ul listed class 1 div 1 flexible coupling. they usually come rated for all classes and divisions and are VERY expensive, if its deisel and your not within another hazardous area thats classified then you can use the FNMC