During the Double-Blind,placebo-Controlled Food Challenge,_____

During the double-blind,placebo-controlled food challenge,_____.

A) ​only the care provider knows whether a suspected offending food or a placebo is being tested
B) only the patient knows whether a suspected offending food or a placebo is being tested
C) neither the patient nor the care provider knows whether a suspected offending food or a placebo is being tested
D) both the patient and the care provider know whether a suspected offending food or a placebo is being tested
E) medical supervision is not needed