Answer
(a) decrease
(b) II
Work Step by Step
(a) We know that if a person is nearsighted, placing the intra-corneal ring should decrease the cornea's curvature, so that the focal length of the eye is equal to the distance from the lens to the retina.
(b) We know that the best explanation is option (II) -- that is, the intra-corneal ring should decrease the curvature of the cornea; hence, it is flatter and bends light less. This will allow parallel rays from far away to be focused.
