(A) says that A (the way historians understand the war) is linked to B (what actually happened). (A) then reasons that since B can’t change, A can’t either. This is the same reasoning used in the stimulus, and it has the same flaw. It assumes that there is nothing beyond what actually happened that can change the way historians understand the war.

(B) is a valid argument. If A (market forces) is influenced by B (governmental actions), then a change in B might result in a change in A.

(C) says that A (some diseases) are caused by B (genetics), and reasons that it should be possible to prevent A by changing B. (C) doesn’t say, like the stimulus, that B can’t be changed and that thus A can’t be changed — in fact, it suggests that by changing B we should be able to change A.

(D) doesn’t have a factor that remains unchanged.

(E) doesn’t have a factor that remains unchanged.