An operations specialist reviewed March advertising data and found that Wednesday's conversion rate was noticeably higher than other days, so they recommended 'investing the entire budget in Wednesdays from now on' and planned to execute the next week directly. According to the five-step induction method, which step is most lacking in this analysis?

Answer: C

• ARedefine the subject, time, and metrics clearly, otherwise induction cannot begin.✗ Incorrect. The stem already specifies the subject (Wednesday ad placements), time (March), and metric (conversion rate), so this step is mostly complete; corresponds to the misunderstanding that the five steps must be mechanically repeated from scratch.
• BRemove special events and incomparable data mixed into March before re-calculating.✗ Incorrect. Data cleaning targets identifiable anomalies or incomparable data, but the stem provides no indication of any special events; corresponds to the over-demand that without item-by-item screening nothing has been cleaned, which is not the most missing step here.
• CCheck another month's data to see whether the Wednesday-highest pattern still holds.✓ Correct. Using only the data that formed the conclusion to prove itself is insufficient; the final step of the five-step method is to validate with new samples. If the pattern persists in another month, credibility increases. The stem jumps to a conclusion and action from March data alone, skipping exactly this step.
• DWeaken the wording of the conclusion, e.g., say 'Wednesday might be better'.✗ Incorrect. Softening wording only makes the statement sound cautious; the pattern itself remains untested; corresponds to the misconception that using a cautious phrasing equals completing validation.