IgE is discovered by multiple choice question:

The correct answer is (a) Ishizaka.

Kimishige Ishizaka and his wife, Teruko Ishizaka, discovered IgE (Immunoglobulin E) in 1966. They identified it as a distinct class of antibodies involved in allergic reactions and parasite immunity. Their work revolutionized the understanding of allergy and led to significant advances in the field.