When did the minister admit his mistake?

The selection of "Last week" as the correct answer indicates that the minister acknowledged his mistake recently, specifically within the past seven days. This implies that the situation is still relatively fresh and may still have ongoing implications or reactions from the public or media. The phrase "last week" provides a clear timeframe, helping to contextualize when the admission occurred, which is crucial for understanding the immediate relevance of the minister's statement.

Options that suggest longer timeframes, such as "This week," "Last month," or "Years ago," do not accurately capture the recent nature of the admission and may mislead the reader about the timing and potential impact of the minister's recognition of his mistake. Each of these alternatives would imply a different context that does not align with the urgency or recent occurrence implied by the correct answer.