<prompt> Direct Coombs test is positive in hemolytic anemia due to:Paraxysmal cold hemoglobinuriaParoxysmal nocturnal hemoglobinuriaIdiopathic thrombocytopenic purpuraHemolytic uremic syndrome  <response>: Paroxysmal cold hemoglobinuria: Caused by the presence of cold-reacting autoantibodies anti-P Ab in the blood - Hence, Direct coombs test is positive. Characterized by the sudden presence of hemoglobinuria, typically after exposure to cold temperatures. 