Which of the following statements provides the best example of how characters communicate the author's purpose in The Number Devil?

Robert thinking it is cool to make a three out of nothing but ones reveals that the author's purpose for writing is to persuade.

Robert dreaming of a meadow where the grass is over his head reveals that the author's purpose for writing is to entertain.

The number devil giving Robert a math problem about pretzels reveals that the author's purpose for writing is to persuade.

The number devil telling Robert why he invented numbers reveals that the author's purpose for writing is to inform.