<prompt> Therapeutic index of drug is indicator of:PotencySafetyEfficacyAll  <response>: Ans. B. SafetyTherapeutic index is ratio of LD50 and ED50. LD50 is defined as lethal dose which kill 50 animals who are given the dose. ED50 is defined as effective dose which is effective in 50 of the population. It is also known as margin of safety. 