What could be a reason the snakes behaved this way, according to one of the researchers?

Which statement best describes the use of the underlined word in the excerpts? in excerpt 1, it refers to personal growth, while in excerpt 2, it suggests the physical act of moving. in excerpt 1, it refers to personal growth, while in excerpt 2, it suggests scientific discoveries. in excerpt 1, it refers to societal advancement, while in excerpt 2, it suggests the gradual march of time. in excerpt 1, it refers to societal advancement, while in excerpt 2, it suggests steps toward a particular goal.