Well, a gerund is a verb that ends in 'ing' and acts as a noun. Among the choices, "Everyone just loves skating!" is the one that has a gerund. "Skating" is a verb, however, in this sentence, it is acting as a noun.
A sonnet is a one-stanza, 14-line poem, written in iambic pentameter. Therefore, the answer is
D. in its number of lines
Cause he was the main character of story