Answer:
1. B. Compete to have the most and biggest weapons
2. Militarism is the mass expansion of a countries Army which could mean more manpower or new weapon technology or even both. For example, the German Empire was militarizing by expanding their military's manpower and creating a new navy plus airforce.
3. B. The sound of shelling artillery affected soldiers brains
4. WW1 used modern technology to fight during the war which include trains, battleships, warplanes, zeppelins, and the tank was introduced during WW1. Also, new types of guns were used such as machine guns and flamethrowers.