Question

Winston Churchill was among the greatest orators (who, whom) the English-speaking world has produced.

Answer 1

The only time "who" is used properly is when it's the subject of the verb. In this case, it appears that the subject of the verb has already been assigned to a noun, making the answer "whom".

Answer 2

Thank you, again, I've been reading and correcting these all morning

Answer 3

It's a pretty weirdly-phrased sentence anyway. I'll help whenever :D