Please help. What events led to the Allied victories in Italy and Soviet Union?

In the final push to defeat the Axis powers of Italy and Germany during World War II (1939-45), the U.S. and Great Britain, the leading Allied powers, planned to invade Italy. Beyond their goal of crushing Italian Axis forces, the Allies wanted to draw German troops away from the main Allied advance through Nazi-occupied northern Europe to Berlin, Germany. The Italian Campaign, from July 10, 1943, to May 2, 1945, was a series of Allied beach landings and land battles from Sicily and southern Italy up the Italian mainland toward Nazi Germany. The campaign seared into history the names of such places as Anzio, Salerno and Monte Cassino, as Allied armies severed the German-Italian Axis in fierce fighting and threatened the southern flank of Germany. The Allied advance through Italy produced some of the most bitter, costly fighting of the war, much of it in treacherous mountain terrain.

The Allies Target Italy: 1943

In Casablanca, Morocco, in January 1943, Allied leaders decided to use their massive military resources in the Mediterranean to launch an invasion of Italy, which British Prime Minister Winston Churchill (1874-1965) called the “soft underbelly of Europe.” The objectives were to remove Italy from World War II, secure the Mediterranean Sea and force Germany to divert some divisions from the Russian front and other German divisions from northern France, where the Allies were planning their cross-Channel landing at Normandy, France.

i really do want to but i just don't know it i'm so sorry : (

i believe the correct answer is b.