Question

Which explains why freeing Italy and North Africa was part of the Allied strategy for winning the war?

~ It would enable the Allies to recruit local military forces.
~ It would stop North African forces from invading Europe.
~ It would help prevent Soviet expansion in the West.
~ It would ultimately ensure victory over Japanese forces.

Answer 1

I am pretty sure that the reason which explains why freeing Italy and North Africa was part of the Allied strategy for winning the war is being shown in the the last option from the scale represented above : It would ultimately ensure victory over Japanese forces. They assumed that if they set Italy and North Africa free they will reach the victory and defeat Japan, so this option is the only suitable.
Hope it helps!

Answer 2

The answer is:

~ It would ultimately ensure victory over Japanese forces.

One of the biggest allies of Germany was Italy, and defeating them ensured the ability to attack Germany from other fronts, by doing so, Japan would have less and less support from Germany and this will lead ultimately to its defeat.