请教沸沸22

22. In 1992, a major newspaper circulated throughout North American paid its reporters an average salary paid by its principle competitors to their reporters. An executive of the newspaper argued that this practice was justified, since any shortfall that might exist in the reporters’ salaries is fully compensated by the valuable training they receive through their assignments. fficeffice" />

Which one of the following, if true about the newspaper in 1992, most seriously undermines the justification offered by the executive?

(A) Senior reporters at the newspaper earned as much as reporters of similar stature who worked for the newspaper’s principle competitors.

(B) Most of the newspaper’s reporters had worked there for more than ten years.

(C) The circulation of the newspaper had recently reached a plateau, after it had increased steadily throughout the 1980s.

(D) The union that represented reporters at the newspaper was different from the union that represented reporters at the newspaper’s competitors.

(E) The newspaper was widely read throughout continental Europe and Great Britain as well as North America.

请问为什么选b，虽然我觉得其他答案也不对，但是不懂为什么选b1

请大家指教～～～