Cool, now ask Russians if they could have done it without lend-lease
Who did the most? I’d say probably the USSR by numbers. The US was a huge driver of the war effort, and used a blend of hard and soft power to push. The UK and (Free) France were necessary resistance and emblematic of the other western efforts. The Battle of Britain can’t be understated, they were a huge stopping block. ANZAC forces weren’t as prevalent in WW2 as they were in WW1 - they weren’t the leading force, but they were present and earned every ounce of respect. In theory, Japan could even be on here as a catalyst - even though they were allied to the Nazis and did many horrifying things, had it not been for Pearl Harbor, the US wouldn’t have gotten involved.
But really I think it is either the USSR or the USA, with the UK a distant but necessary third.
I do love the folks putting troll answers in like Belgium though.
A huge majority of those who actually lived through WWII gave credit to the Soviets, who killed the most Nazis by far.
Given that the survey is in English, I’m guessing mostly people from English speaking countries took it.