Lao Zhang's noodle shop changed its menu at the beginning of March, and that month's customer flow dropped by 20%. He concluded that the new menu drove customers away and decided to switch back to the old menu immediately. A neighbor reminded him that road construction started on that street at the beginning of March, and pedestrian traffic visibly decreased. Which evaluation is the most accurate?

Answer: D

• AThe menu change happened before the drop in customers, and this order of events is enough to prove the new menu is the cause.✗ Wrong. The fact that the change came before the drop only establishes a temporal sequence, not a causal one; this is the 'post hoc, ergo propter hoc' fallacy.
• BSince the road construction also affects customer flow, the menu is completely irrelevant, and the result would be the same whether the menu is changed or not.✗ Wrong. Discovering another possible cause does not mean the menu has no effect at all; jumping from 'there is another cause' to 'this cause is ruled out' is an unsupported conclusion.
• CThe drop in customers is a coincidental combination of multiple factors and cannot be analyzed; one should just rely on years of experience and decide directly.✗ Wrong. Giving up analysis because of multiple possible causes is acting on intuition; the correct approach is to list possible explanations and seek evidence to distinguish them, not to refuse analysis.
• DThe drop in customers only coincides with the menu change; the road construction might be the main cause, so one should first determine the real cause before deciding.✓ Correct. The drop merely coincides with the menu change, and the road construction may be a more direct cause; investigating first and then acting avoids the risk of fixing the wrong cause and making things worse.