<prompt> In which phase post marketing surveillance is done:Phase IPhase IIPhase IIIPhase IV  <response>: Ans. D. Phase IVPhase - 1 first in human. Done for toxicity and pharmacokinetic studies. Phase - 2 mainly done for safety and efficacy. Phase- 3 done on large number of patients detecting the efficacy. Phase -4 is post marketing surveillance done which detect the rare side effects which were not detected in above phases. 