Answer:
Dimmesdale defends and praises Hester in his speech, which would be very strange behavior for a reverend like him.
Explanation:
Hester has an illegitimate daughter and refuses to say who the child's father is. As she lives in a Puritan society where patriarchy and conservatism reigns, she suffers prejudice and insults from the whole society. However, Reverend Dimmesdale (a cleric who should abolish Hester's sin) gives a speech in favor of Hester, where he praises her and reinforces her qualities. This is very strange behavior, which made the whole community suspicious.
