In spite of what its critics say, the new, expensive artificial kidney implant is a boon to modern medicine. These critics should remember that the first heart transplants stimulated an enormous amount of beneficial medical research, even though the transplant technique was later rejected in favor of less invasive surgical procedures.
The author defends the artificial kidney implant against the critics by
A. attacking her opponents' method of circular reasoning
B. implying an analogy between the benefits of the artificial kidney implant and the benefits of the early heart transplants
C. pointing out a contradiction implicit in their criticism of the implant's high cost
D. criticizing the professional objectivity of her opponents rather than their claim
E. implying an analogy between the critics' opposition to the artificial kidney implant and their opposition to the early heart transplants