The Men Who x The Men Whom

I already know that "Who" is a subject pronoun and "Whom" an object pronoun, but there's a specific sentence which is getting me "confused" about it.

Which one of these sentences is written in the right, or at least the more acceptable, manner:

"The men who were designated to build the whole hotel." or
"The men whom were designated to build the whole hotel"?

If you could also explain me why, I'd appreciate.

Thank you in advance :)
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Avatar do usuário Ricardo F. Bernardi 10885 17 218
Good morning, Nickolas

Both sentences are correct.
"Whom" is more formal than "who".

You should read:

Enjoy your studies!

(1) Pearson Education. Longman Dictionary. 2004.