Question

Why did Russia send troops to the border of Austria-Hungary in 1914?
Austria-Hungary had invaded Serbia, and Russia was in an alliance with Serbia.
Austria-Hungary was threatening to invade Russia.
Austria-Hungary was sending its people to live in Russia.
Austria-Hungary needed help resisting a German invasion.

Answer 1

Answer:

Austria-Hungary had invaded Serbia, and Russia was in an alliance with Serbia.

Answer 2

Answer:

A. Russia had an alliance with Serbia, and Germany had an alliance  with Austria-Hungary.

Explanation: