The most widely used therapy for a certain type of ulcer completely heals such ulcers in 44 percent of patients within six months. In a six-month trial of a new therapy for this type of ulcer, 80 percent of ulcers treated achieved significant healing and 61 percent were completely healed. Since the trial treated only ulcers of this type that were worse than average, the new therapy clearly promotes healing more effectively than the most widely used therapy.
The answer to which of the following would be most useful in evaluating the argument given
A．What differences are there, if any, in the ways that the two therapies are administered
B．Is there any significant difference between the costs associated with the two therapies
C．What percentage of people with ulcers of this type who were treated with the most widely used therapy for six months experienced significant healing
D．How quickly do ulcers of this type, if left untreated, become significantly worse
E．(E) What percentage of patients involved in the six-month trial of the new therapy were disappointed at the rate of healing that were experiencing