The solar eclipse achieves totality only in limited geographical regions because
(a) The size of the shadow of the moon on the earth is small as compared to the cross section of the earth
(b) The earth is not smooth flat surface, but has elevations and depressions
(c) The trajectories of the earth around the sun and the moon around the earth are not perfect circles
(d) Sun rays can reach most of the peripheral regions of shadow of the moon due to atmospheric refraction
