The angle of elevation of the top of an unfinished pillar at a point 150 m from its base is 30°. If the angle of elevation at the same point is to be 45°, then the pillar has to be raised to a height by how many metres?
(a) 59.4 m
(b) 61.4 m
(c) 62.4 m
(d) 63.4 m