Which of the following did not occur after germany invaded the soviet union? germany was engaged in a double-fronted war. the german troops endured a harsh winter, for which they were not prepared. the soviet union made an agreement with great britain to come to each other's aid and fight against

Are you sure you typed all the choices?  All three of those things were things that happened following the German invasion of the USSR during World War II.  What didn't happen was a German victory.  The war between Germany and the USSR on the Eastern Front was long and brutal, costing many lives.  But the Soviet Union eventually prevailed and then advanced against Germany itself.