This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other topics and Adverse effects, Subject name: Anatomy
Which of the following terms best describes a drug that blocks the action of adrenaline at its receptors by occupying those receptors without activating them 
Select and explain. 
A. Pharmacological antagonist, B. Non competitive antagonist, C. Psychological antagonist, D. Chemical antagonist
A: Pharmacological antagonist
Answer: A: Pharmacological antagonist 
Explanation: Ref-Katzung 10/e p16 pharmacological antagonism. the relationship between drugs in which an antagonist inhibits the activity of an agonist by reacting with the receptor or other pa of the effector mechanism.