题目选项分析

A country's Aeronautics Board (AB) employs inspectors who make routine annual inspections of all aircraft. On inspecting Azura Airlines' airplanes in December, they reported considerably more violations of AB rules this year, compared to a year ago. This fact explains why Azura had more accidents this year, compared to last year.

Which of the following, if true, would cast most doubt on the conclusion in the passage?

【选项】The AB increased the length and rigor of its inspections this year, compared to last year.