Passage Summary: Good short story writers usually aren't great novelists because the two crafts require opposite skill sets that rarely overlap in one person.

Conclusion: It is rare for excellent short story writers to also be great novelists.

Reasoning: The two forms of writing require different, almost conflicting skills, and it is rare for one person to possess both.

Analysis: The structure is: Group A is unlikely to be successful in Category B because A requires Skill X, B requires Skill Y, and Skill X is actually detrimental to B. Finally, it notes that having both X and Y is rare. To parallel this, look for an answer that follows this 'conflicting requirements' structure: doing one thing well involves a trait that hinders the other, and having both traits is uncommon. The logic relies on a mutual exclusivity between the specific demands of two related but distinct fields.