Answer:
D). To Entertain.
Explanation:
In the given excerpt from '"The Crab That Played with the Sea"('Before...what to play at'), the author's chief purpose is 'to entertain' the readers. The imagination of the creation made by the Eldest Magician in a sequential story-like manner('first..got..earth ready, sea..ready, then..told animals..to come and play') fascinates and amuses the readers. The latter description of the unique play by the Magician and each animal's part/role in it(he took..elephant..all-the-elephant-there-was..played at') captivates the readers' interest and keep them engaged. Thus, option D is the correct answer.
