Answer:
d. plateau effect
Step-by-step explanation:
The plateau effect is a reaction of adaptation of our body to a stimulus, causing the effect of this stimulus to "park" at its greatest strength, ie the plateau effect explains why a drug can reach its maximum effect regardless of the dose taken. This is because our body gets used to the new condition (in this case, the effect of the medicine) that has been imposed and now reacts quickly and extremely susceptibly to this condition.