13. Defense department analysts worry that the ability of the US to wage a prolonged war would be seriously endangered if the machine-tool manufacturing base shrinks further. Before the Defense department publicly connected this security isue with the import quota issue, however, the machine-tool industry raised the national security issue in its petition for import quotas.

which of the following, if true, contributes most to an explanation of the machine-tool industry's raising the issue above regarding national security?

A.when the aircraft industries retooled, they provided a large amount of work for tool builders.

B. The defense department is only marginally concerned with the effects of foreign competition on the machine-tool industry.

C. the machine-tool industry encountered difficulty in obtaining governmental protection against imports on grouds other than defense.

D. a few weapons important for defense consist of parts that do not require extensive machining.

E. several federal government programs have been designed which will enable domenstic machine tool manufacturing firms to compete successfully with foreign toolmakers.

answer: C

为什么B 不对呀？