Answer: Superego
Explanation: According to Freud, the superego is part of the mind that regulates, the moral ethical aspects of personality. In addition, there is an ID as part of the mind that "engages in" personal gain, and an ego that is a balance between ID and superego. Superego is a part of the mind that "forces" us to be moral, to keep our word, to evaluate the harm we have done to others and to ourselves. Thus, the sense of guilt is naturally linked to this part of the mind that encourages us to think and feel guilty if we depart from moral principles.