In The Sherlock Society, what kind of roads will Grandpa no longer drive on after laying down his ground rules?

• A. Dirt
• B. Gravel
• C. Asphalt
• D. Mud

Answer: (A)

When a character sets down ground rules for driving, the change is about what surfaces are considered acceptable. Dirt roads are unpaved and tend to be dusty, uneven, and less predictable than paved routes. If Grandpa wants a cleaner, safer, or more reliable drive, dirt roads are the easiest kind to exclude, because they violate those smoother, more controlled expectations. Asphalt is smooth and paved, so it clearly fits under such rules; gravel, while rough, is still a common, negotiable surface; mud depends on weather and isn’t a fixed road type. So dirt roads are the best match for the kind of restriction implied by laying down clear driving rules.