157) ANSWER

B) Antigen-IgE-mast cell interaction.

RATIONALE

Type I hypersensitivity reactions are caused by widespread antigen-antibody reactions such as anaphylaxis. These responses are usually immediate and lead to an antigen-antibody complex that causes the release of histamine. Option 4 is an explanation of what occurs with a blood transfusion reaction. Option 3 is an explanation of a Type IV delayed hypersensitivity. Option 1 is false. This question requires knowledge about hypersensitivity responses.