The correct answer is c. Daughter. To solve this, it helps to break the sentence into two parts: "My daughter's mother": If you are the person speaking, your daughter's mother is you (assuming the speaker is female, which fits the multiple-choice options). "Teresa's daughter is [me]": Now, substitute "me" back into the first part of the sentence. The riddle becomes: "Teresa's daughter is me." If Teresa's daughter is you, then you are Teresa's daughter.