I don't think there is a problem with the word ambiguous assuming the context explains the ambiguity better than this sentence alone does. When we say something like "Who this individual is who deserves to be free" it tends to focus on the quality or character of that person. The 1st and 3rd options both are more steered toward the ambiguity being whether it's this person or that person. I think they all work ok, but not great. Maybe more context would help.

Thank you Charles. I am not native English speaker and it is what I have learnt in a British Institute here in my country. Do you think my answer is completely wrong or could exist a difference Due to US English and UK English?

Option 1 is better in terms of sentence structure. However, the word "ambiguous" seems wrong here. It's definitely not correct word usage here. Either the idea presented here is wrong, or the writer is translating from his or her own language. A native speaker/writer of English would not say: "It is ambiguous to discuss . . ." That needs to be re-written. Greetings! Teacher Charles, https://www.italki.com/teacher/5853252 Sorry, Leonardo. Indirect speech in this example would be an example of poor English sentence structure.

Hi Hernandez. The second one is the right option. Basic indirect speech structure. Verb BE at the end of the sentence Espero te sea útil. Saludos desde Uruguay

The second one sounds most natural to me. Unfortunately, I can’t give you a rule to explain why.