This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General Pharmacology, Subject name: Pharmacology
Therapeutic index is measure of: 
Select and explain. 
A. Safety, B. Efficacy, C. Potency, D. Selectivity
A: Safety
Answer: A: Safety 
Explanation: Ans. (A) Safety(Ref: KDT 8th/65)Therapeutic Index (TI)It is a measure of the safety of a drug.It is calculated as a ratio of LD50 to ED50.Drugs having high TI are safer whereas those having low TI are more likely to be toxic.