After what event did the first declaration of war occur in world war 1

A month after the assassination of Archduke Franz Ferdinand and his wife Sophie, on July 28, 1914,

Explanation:the Austro-Hungarian government declares war on Serbia. Immediately, and within a period of six days, European countries declare war upon one another.

the answer is b: the religion they practice.

here's why:

there were many different native american tribes and those with similar characteristics formed a main tribe or nation. each had its own language, religion and customs.

b. they tried to evict the squatters from the area.

so sorry if wrong