The correct answer should be are unwise in attempting to achieve a positive relationship with Britain
He doesn't say that they are not allowed, but that it is extremely nonsensical and foolish to even try to do.
I think it's C. Heavy means the sigh was long, and obviously loud. Wind through a tomb is used as a metaphor that the sigh was lonely. Lonely means nobody is there, and nobody is there to hear wind go though a tomb, and anyone in the tomb can't hear, because, well, they're dead.
Answer:
When writing a restrictive clause, introduce it with the word "that" and no comma. However, if the subject is or was a human being, use "who" to introduce the clause. When talking about people in defining (restrictive) relative clauses, who is preferred to that.
Hopeful because he had hopes that one day he too could be freed
