Bumblebee served under him . Bulkhead was in charge of all of Cybertron 's space bridges . And Ratchet was retired on some quiet planet with a pink and white femme that he 'd known from before . They were all gone .

Question: What may have been true of them in the past ?
Answer: They had served on a quiet planet .None of the above choices .They had met once on a bridge .They were closely connected with one another .