​The placebo effect is

A) ​most prominently observed in well-designed experiments.
B) ​an imaginary effect which can be applicable to everybody.
C) ​an imaginary effect occurring almost exclusively in hypochondriacs.
D) ​physiologically real and can improve organic or psychological symptoms.

Placebo Effect

A beneficial effect that cannot be attributed to the properties of a placebo itself, and must therefore be due to the patient's belief in the treatment.

Imaginary Effect

A perceived outcome or result that does not have a basis in physical reality, often associated with placebo effects.

Hypochondriacs

Individuals who excessively worry about having a serious illness despite the absence of medical evidence to support their concerns.