Trench warfare led to stalemates during World War I by making it A) difficult for attacks to succeed. B) easy to attack the enemy. C) difficult for soldiers to fight. D) easy for soldiers to fight.

The answer is A. D ifficult for attacks to succeed.

During the world war I, trench warfare focused on creating defensive line near the border between two countries.

The trench warfare provides each armies with the maximum protection, but it also make it really hard to kill enemies, which make many wars eventually led to stalemate.