It can be inferred from the passage that the intransigent physician______.
A．continues to prescribe a drug even though he knows it is not in the best interests of the patient
B．refuses to use a drug for an unlabeled purpose out of fear that he may be stigmatized by its use
C．persists in using a drug for disapproved uses because he rejects the evidence of its ineffectiveness or dangers
D．experiments with new uses for tested drugs in an attempt to find medically beneficial uses for the drugs