What was the main reason for the start of world war 1

The main reason for the start of World War One was the assassination of Archduke Franz Ferdinand

Explanation:

 The assassination of Archduke Franz Ferdinand was the main reason for the start of ww1

Explanation: Many countries had alliances with each other and when he was assassinated, war was being used as a threat and since countries were in alliances they got involved with the conflict and that why it was call a world war.

answer: your option is d

explanation:

the monroe doctrine is the best known u.s. policy toward the western hemisphere. buried in a routine annual message delivered to congress by president james monroe in december 1823, the doctrine warns european nations that the united states would not tolerate further colonization or puppet monarchs.