A city asserts that a new bus route reduces commute time for most riders.

• A. The route's data were collected during a holiday week with lighter traffic.
• B. The route's travel time is highly variable due to traffic.
• C. The route serves only a small portion of commuters.
• D. The route has high fare compared to alternatives.

Answer: (A)

The main idea is that evidence used to claim a broad benefit must come from data that reflect typical conditions, not unusual ones. If the measurements were taken during a holiday week when traffic is lighter, the observed commute times are easier to improve simply because there’s less congestion, not necessarily because the new bus route genuinely reduces time for most riders under normal conditions. This creates a bias in the data and undermines the claim’s general applicability—external validity is compromised. So, this data source best explains why the claim could be overstated, since it doesn’t represent everyday commuting. The other factors—great variability in travel time, serving only a small portion of commuters, or higher fare—don’t directly address whether the time savings would apply to most riders during typical conditions.