Bigbook p.90 T2S4 Q17

"17. The primary purpose of the passage is to treat the accepted generalizations about organ transplantation in which of the following ways?

A) Explicate their main features
(B) Suggest an alternative to them
(C) Examine their virtues and limitations
(D) Criticize the major evidence used to support them
(E) Present findings that qualify them"

Why is answer choice B incorrect? isn’t the rat case an alternative to the generalization as the normal rules of the generalization no longer applies? Thanks.