The Nurse Admits a Patient to an Oncology Unit That

The nurse admits a patient to an oncology unit that is a site for a study on the efficacy of a new chemotherapeutic drug. The patient knows that placebos are going to be used for some participants in the study but does not know that he is receiving a placebo. When is it ethically acceptable to use placebos?

A) Whenever the potential benefits of a study are applicable to the larger population
B) When the patient is unaware of it and it is deemed unlikely that it would cause harm
C) Whenever the placebo replaces an active drug
D) When the patient knows placebos are being used and is involved in the decision-making process