15. In the effort to fire a Civil Service employee, his or her manager may have to spend up to $100,000 of tax money. Since Civil Service employees know how hard it is to fire them, they tend to loaf. This explains in large part why the government is so inefficient.

It can be properly inferred on the basis of the statements above that the author believes which of the following?

I. Too much job security can have a negative influence on workers.

II. More government workers should be fired.

III. Most government workers are Civil Service employees.

(A) I only

(B) I and III only

(C) II only

(D) I, II, and III（A）

(E) III only

我选B，我认为III.Most government workers are Civil Service employees是作者的assumption，I是结论。两个都可以说是the author believes 的东西，为什么只有I对？