Answer
(a) farther from
(b) II
Work Step by Step
(a) We know that if an object moves closer to an octopus, the image produced by the lens will be farther behind the lens. Thus, in order to keep the object in focus, the octopus must move its lens farther from its retina.
(b) We know that the best explanation is option (II) -- that is, when the object moves closer to the eye, the image produced by the lens will be farther behind the lens; therefore, the lens must move farther from the retina.
