A patient develops severe itching, swelling of the lips, and difficulty breathing within minutes after being stung by a bee. Laboratory tests show elevated levels of IgE antibodies specific to bee venom. Which type of hypersensitivity reaction best explains this response?

A patient accidentally receives a blood transfusion containing incompatible red blood cells. Shortly afterward, the patient's immune system produces antibodies that bind to antigens on the transfused red blood cells, leading to complement activation and rapid destruction of those cells. Which hypersensitivity mechanism is responsible for this reaction?

A laboratory animal is repeatedly exposed to a soluble protein antigen. Several days after exposure, immune complexes composed of antigen and IgG antibodies accumulate in the walls of small blood vessels, leading to complement activation and localized inflammation. Which type of hypersensitivity reaction best describes this process?

A 27-year-old woman develops an intensely itchy rash with small vesicles along the area where a new metal bracelet contacts her wrist. She reports that the rash appeared about 48 hours after she first wore the bracelet. Physical examination shows erythema and vesicles confined to the contact site. Which immunologic mechanism most directly mediates this reaction?