Question

which of the following occurred after allied forces invaded the italian mainland in september 1943?
axis forces repelled the allies.
italian forces quickly surrendered.
allied forces declared victory in europe.

Explanation:

After the Allied forces invaded the Italian mainland in September 1943, the Italian government surrendered. However, German forces continued to fight in Italy. Axis forces (mainly German) did not repel the Allies. Allied forces declared victory in Europe in May 1945 after Germany's surrender. Italian forces (the new government after the ousting of Mussolini) surrendered, not quickly in a sense that there was still German resistance. But among the options, the surrender of Italian forces (after the invasion) is the relevant event.

Answer:

Italian forces quickly surrendered.