I know they taught you at camp to use your rifle and bayonet, but that could get you killed. The best answers are "B" and "D". Short shovels are the best. You can swung them, thrust and cut with the sharp bottom edge, or swing down and hammer someone. Picks, clubs, maces also allow you to hit hard in crowded conditions - and that might win the fight for you. The problem with a rifle and bayonet is that it's too long. In a trench fight you don't have the space to use it. The butt of your rifle makes a good club in an emergency, however. As for pistols - only officers have pistols - not you - and in crowded conditions the shot could hit the wrong person.