4. (B)
Question Type: Application
We should not disapprove of the revelation of the truth, even when that truth is unpleasant or potentially harmful. We want to choose an example that illustrates this principle. In (B), scientific information should be freely available even though it can lead to the creation of destructive weapons. This is an exact illustration of the principle, in the realm of science. In this answer choice, science is revealed even though such revelation could cause future harm. Each of the other answers is missing an element of "truth," "pernicious," harms, or revelation of the truth.
(A) speaks of foregoing potential benefits but it does not speak of the "pernicious" harms we care about.
(C) is precisely the opposite of the given principle; it states that truth should be revealed regardless of how it affects a patient’s recovery; this.
(D) is incorrect because it applies a cost-benefit analysis while the above principle implies that truth should always be revealed regardless of its beneficial or harmful effects.
(E) is incorrect because it too argues against revealing the truth, directly contrary to our principle.