What type of figurative language is "it speaks for itself"? for example: the facts speak for themselves.

What is one way that “the maori: genealogies and origins in new zealand” contrasts with “the raven and the first men: the beginnings of the haida”? a.the maori myth features courage, but the haida myth does not. b.the maori myth features community, but the haida myth does not. c.the maori myth features the gods, but the haida myth does not. d.the maori myth features deception, but the haida myth does not.