It was a very deadly war--the Great War produced new forms of guns, bombs, and gas weapons which proved to be devastating.
The Great War, World War I, saw the emergence of tanks, rapid fire machine guns, grenades, mustard gas, and well as airplanes. The method of trench warfare in addition to highly accurate and deadly weapons led to both large numbers of causalities and stalemates. These weapons made it difficult to move position causing need for new techniques or new technology to allow movement.
The answer to the question is A.
Congress created courts and may impeach judges
The Jewish would eat matzo at the day of Passover