弱弱的问一到看起来挺简单的逻辑题

请教NN们一道逻辑题，感谢一下先：

As one who has always believed that truth is our nation’s surest weapon in the propaganda war against our foes, I am distressed by reports of “disinformation” campaigns by American intelligence agents in Western Europe. In a disinformation campaign, untruths are disseminated through gullible local journalists in order to damage the interests of our enemies and protect our own. Those who defend this practice say that lying is necessary to counter Soviet disinformation campaigns aimed at damaging America’s political interests. These apologists contend that one must fight fire with fire. I would point out to the apologists that the fire department finds water more effective.

10.   The author of the passage above bases his conclusion on which of the following?（题目问的是什么意思？）

(A) A circular definition of “disinformation”

(B) An example of the ineffectiveness of lying as a weapon in the propaganda war

(C) An analogy between truth and water

(D) An appeal to the authority of the fire department（C）

(E) An attack on the character of American intelligence agents in Western Europe

11.   The author’s main point is that（A,B好像也有道理啊）

(A) although disinformation campaigns may be effective, they are unacceptable on ethical grounds

(B) America’s moral standing in the world depends on its adherence to the truth

(C) the temporary political gains produced by disinformation campaigns generally give way to long-term losses

(D) Soviet disinformation campaigns have done little to damage America’s standing in Europe（E）

(E) disinformation campaigns do not effectively serve the political interests of the United States

the answers are C, E