​A direct, consistent relationship between the independent variable and the dependent variable

A) ​is an example of the placebo effect.
B) ​is an example of the nocebo effect.
C) ​defines dose-response relationship.
D) ​indicates a transverse relationship.

A direct, consistent relationship between the independent variable and the dependent variable defines a dose-response relationship. This means that as the dosage of the independent variable increases, the magnitude of the effect seen in the dependent variable also increases. This relationship is often studied in fields like pharmacology and toxicology. The placebo effect (A) and nocebo effect (B) both refer to the psychological effects that can be seen in individuals when given an inactive treatment or a treatment with negative connotations, respectively. A transverse relationship (D) is not a commonly used term in scientific research, and is not relevant to this question.