<prompt> Which phase of clinical trials is done after the drug enters the market?Phase IPhase IIPhase IIIPhase IV  <response>: Ans. D Phase IVRef: KDT 8the 91Clinical TrialOther NamePhase 0Microdosing studiesPhase IHuman pharmacology and safetyPhase IITherapeutic exploratoryPhase IIITherapeutic confirmatoryPhase IVPost marketing surveillance 