Why was the french ivasion of russia a failure?

Because the french army pounded its way into the western front of Russia, but the Russians were actually just retreating and letting the french come in. The winter set in, and none of the french troops had efficient winter gear. Many died. Retreat was a must, this has a large impact on the Russian way of thinking though, many Russians troops were exposed to the Napoleonic Code. this led to to many reformist thinkers in Russia soon after. 

Ithink the answer is b.)

What he said