I would say D. sorry if not.
Answer:
A standing army, unlike a reserve army, is a permanent, often professional, army. It is composed of full-time soldiers (who may be either career soldiers or conscripts) and is not disbanded during times of peace. It differs from army reserves, who are enrolled for the long term, but activated only during wars or natural disasters, and temporary armies, which are raised from the civilian population only during a war or threat of war and disbanded once the war or threat is over. The term dates from approximately 1600, although the phenomenon it describes is much older
Explanation:
Russia was successful in defeating Napoleon's troops due to the weather. Napoleon had far superior troops and technology, he just left at the wrong time of the year. His men were not prepared. They were not ready for freezing temperatures. They left in the summer and didn't pack their wool uniforms because they had assumed it would be a quick win. This will also lead to Napoleon's downfall as he turns an ally into and enemy must then fight a 2-front war (fight on both sides: British in the West and Russians in the East).
