The convex lens bends the light rays and help focus the image on the retina which was otherwise being focused behind the retina by a less flexible lens or shortened eye ball; option B is correct answer. If the image was being focused in front of retina, as is the condition in myopia caused by elongated eyeball, the person would need a concave lens to diverge the light rays and thereby focus the image on the retina. This makes option C incorrect. Rods and cones are the secondary photoreceptors that are present buried under the layer of blood vessels and nerve fibres throughout the retina. The point of exit of optic nerve from eye forms a “blind spot” in retina which is devoid of both rods and cones and hence no image is formed on it. This makes option D incorrect. Yellow spot is the central oval shaped pigmented area in retina which is rich in cones and serves in providing finer details of the object. This makes option A incorrect. Correct answer is B.