<prompt> The postmarketing trial comes underPhase 1 clinical trialPreclinical trialPhase 3 clinical trialPhase 4 clinical trial  <response>: There are 4 phases of a clinical trial. Once the drug is released into market pharmacovigilance is done - comes under phase 4 of drug trial to asses the safety, cost effectiveness of the drug once marketed Ref: K.D.Tripati.7th ed. Pg 82-83 