<prompt> Which indicates least chances of re-bleeding after hematemesis episodes:Adherent clot on ulcerClean based ulcerGastric ulcer with AV malformationVisible bleeding vessel.  <response>: Most patients of hematemesis have a rebleed within the next 3 days of an episode. UGIE is diagnostic as well as prognostic as a clean based ulcer has a least chance of re-bleed while visible bleeding vessel has the highest chances. 