What was the key challenge faced by the allies during world war ii?

lack of funding for the war

war was fought mainly by the navy

lack of public support for the war

war was fought on multiple fronts

"War was fought on multiple fronts" is the one among the following choices given in the question that was the key challenge faced by the Allies during World War II. The correct option among all the options that are given in the question is the last option or the fourth option. I hope that the answer helped you.

The  ancient egyptians  who  built the pyramids  may have been  able  to move massive stone blocks across the desert by wetting the sand in front of a contraption  built  to pull the heavy objects