What was the impact of the use of machine guns and barbed wire during world war i?

i think the answer would happen to be the letter b

because the bar never runs out

couples always argue

the answer is b just took the test

the conditions that made the byzantine empire vulnerable to attacks by the muslin turks were the sack of constantinople by western crusaders, the conquests of the sultanate of rum, presence of rival kingdoms and finally the set up of fiefdoms at the empire which were owned by the ghazis (turkish warriors).