The following two questions are based on the following passage:
The Southfork Steel Company is in trouble. Since 1960 it has made guaranteed payments to retirees out of a pension fund paid into by current employees as a percentage of their salaries. The restructuring of the Southfork workforce, however, has meant that fewer employees are now needed to produce the same amount of work as in the days of the retired employees. Since current employees are unwilling to pay a larger percentage of their salaries into the pension system than their predecessors did, the pension fund will inevitably go bankrupt.
Which of the following, if true, casts the most doubt on the conclusion in the passage that the pension fund will inevitably go bankrupt ？（）
A. The pension fund is invested in a conservative portfolio of bonds and money market funds that perform, on average, slightly better than inflation.
B. Financial analysts have determined that, with current levels of payments into and out of the plan, the pension fund will remain solvent for at least another seven years.
C. If the company is bought or goes out of business, the payments to retirees from the pension funds are likely to become subject to arbitration by either the new owners or the bankruptcy trustees, in which case the "guaranteed" payments could be readjusted to lower levels, or possibly terminated.
D. The restructuring of the workforce has dramatically increased the efficiency of steel production at Southfork, resulting in substantially higher revenues per employee than in the past, and consequently much higher salaries.
E. Although the modern era is referred to as a "postindustrial" age, the worldwide demand for steel has never been higher.
