Passage Summary: Writers either know they're right or know they're wrong, so they never actually have a reason to open a grammar book.

Conclusion: Grammar books are of no use to authors as reference tools.

Reasoning: Authors won't write sentences they know are wrong, and they won't check books for sentences they are sure are right.

Analysis: The novelist's argument suffers from a false dilemma, assuming that writers are always in a state of total certainty or total awareness of their errors. It ignores the vast middle ground of writers who are simply 'unsure' and use a grammar book to resolve that uncertainty. Look for an answer that points out the failure to consider the writer who isn't sure if a sentence is grammatical and seeks a reference to find out. The novelist seems to think writers have the ego of a god and the self-correction of a computer, leaving no room for the humble 'maybe' that keeps the reference book industry alive.