It is in the introduction and then restated in the conclusion. Each supporting detail is then referred to in each of the body paragraphs one by one. The question is worded very oddly in my opinion so I would say introduction because it fits that answer best, but it could technically be all of them.
Lady Macbeth: she worries her husband is too kind-natured to be able to take the crown however is determined to assist him. She calls on demonic spirits to help her.
Macbeth: he is not convinced, even though his ambitious thoughts led him to think about it previously, Lady Macbeth starts convincing him - this shows him as weak-willed.
