Añadir Índice único en tu mesa:
ALTER IGNORE TABLE `TableA`
ADD UNIQUE INDEX (`member_id`, `quiz_num`, `question_num`, `answer_num`);
Otra forma de hacer esto sería:
Agregue la clave principal en su tabla, luego puede eliminar fácilmente los duplicados de su tabla usando la siguiente consulta:
DELETE FROM member
WHERE id IN (SELECT *
FROM (SELECT id FROM member
GROUP BY member_id, quiz_num, question_num, answer_num HAVING (COUNT(*) > 1)
) AS A
);