Since the predicate is compound ("lays an egg . . . and . . . will roll"), the sentence requires a subject that is appropriate to both parts of the predicate. Based on this requirement, (A) implies that the auk itself, if accidentally kicked, will roll in a circle. (B) makes a cosmetic change but does not fix this problem. So we eliminate (A) and (B). Look for an answer choice that fixes the problem, either by providing a subject appropriate to both parts of the predicate, or by changing the structure of the sentence to eliminate the problem.

(C), (D) and (E) all fix the problem by making "egg" the subject, with the compound predicate "are/is extremely pointed and . . . will roll". However, (C) uses the awkward "the auk being a bird", so we eliminate (C).

(D) violates subject/verb agreement by using "the egg . . . are". This error is made less clear by inserting the plural nouns "rocky ledges" and "sea cliffs" between the subject and verb. However we eliminate (D), and this leaves us with choice (E), our correct answer.