Question: What are the benefits of anti-allergen vacuum cleaners?

  Options: 
 A. Even though they are much more expensive, anti-allergen vacuum cleaners, by preventing allergens from being present in you home, will keep your family much healthier in the long run.
 B. Even though they are much less expensive, anti-allergen vacuum cleaners, by preventing allergens from being present in you home, will keep your family much healthier in the long run.
Answer: A