Which sentence uses a colon correctly? (4 points)

manatees need only a few things to survive up to age 60, enough food and to be left alone.
manatees need only a few things to survive: up to age 60 enough food and to be left alone.
manatees need only: a few things to survive up to age 60, enough food and to be left alone.
manatees need only a few things to survive up to age 60: enough food and to be left alone.