Aspen,
I think the case is very similar to this question:
viewtopic.php?t=850 Note that that question is in the PowerScore course book, in Lesson 1, with the Must Be True questions. In that question, "warm bath" looks like new information, and it is, but the answer is claiming that the warm bath, given that it raises temperature, would have the effect given in the stimulus. That doesn't really count as new information, because the means by which the "new information" is filling a role is by saying something already covered by the stimulus.
It's similar here. Surgical intervention is new. But what is the surgery doing in answer choice (D)? Implanting and sustaining living nerve tissue. That isn't new info - that's a requirement for the preservation of a nerve sheath in some cases in the stimulus. So answer choice (D) is not saying that surgical intervention will preserve living tissue, but saying something like "if living tissue is preserved via surgery, then..." It's not claiming the new info of surgery having an effect, but saying something like "if surgery, for instance, had the effect of preserving living tissue, then a certain consequence has more chance of resulting." Because that consequence and the preservation of living tissue are already covered by the stimulus, we don't have any objectionable new information.
Robert Carroll