Answer: A) Russian troops won several battles but suffured extremly heavy casualties.
Step-by-step explanation:
After initial successes, the Russians had to withdraw.
The war on the Eastern Front involved conflicts with Austria - Hungary and Germany in Prussia, Galicia and Poland. The first conflicts with the Austro-Hungarian army brought good results for the Russians, it happened already in the first year of the war. The advance of the Russians encouraged Germany to withdraw part of the troops in aid of Austria-Hungary, which happened in February 1915.
By joint action, the Russians were repulsed. The balance of power on the battlefield changed and the Russians were on the defensive. In 1916 the Russians tried unsuccessfully to report several offensives and a year later the revolution prevented a new counterattack. Russia had a lot of problems throughout the First World War. The underdeveloped industry predicted a shortage of weapons, clothing and footwear as well as food for the soldiers. That is why the Russians lost the most soldiers during the war.