To quickly answer this question, we must form pairs. 1 says 'his idea to use sign language...'. We must find the noun to which the possessive pronoun 'his' refers. Logically it refers to Pedro Ponce, as he is the one who created the sign language. Thus 4 and 1 form a pair. Also, only 5 can be the opening sentence, as it introduces the idea that for millennia, people with hearing impairment encountered marginalization. How they were marginalized can be seen in statement 3 . Thus 5 and 3 form a pair. 5341 form a coherent para. There is no place for statement 2