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. What percentage of patients involved in the six-month trial of the new therapy were disappointed at the rate of healing were experiencing?