This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
The ratio of the dose that produces toxicity to the dose that produces a clinically desired or effective response in a population of individual is known as: 
Select and explain. 
A. Efficacy, B. Potency, C. Therapeutic index, D. Partial agonist
C: Therapeutic index
Answer: C: Therapeutic index 
Explanation: None