Select the correct answer. what was one of the causes of tensions in europe that led to world war i?

a the nations in eastern europe wanted to unite as a single nation under the ottoman empire.

b germany, austria-hungary, and russia promised to send military support if a war broke out in europe.

c france, germany, and other nations were competing for overseas territory in africa and other places.

d britain cut off germany’s supply ships, and the german people were slowly starving.