PT 28 S3 Q25

The interstitial nucleus, a subregion of the brain's hypothalamus, is typically ... ...

Which of the following statements, if true, most seriously weakens the argument?
(A) No female cats have been known to contract disease X, which is a subtype of disease Y.
(B) ...
(C) ...
(D) ...
(E) ...

*This question is included in Practice Set: "Weaker" Questions, Set 3 - Difficult/Uncommon Mix (25Q)