What is the act of transferring the obligation of the mortgagor to another party called?

The correct answer is assumption. In the context of mortgages, an assumption occurs when one party takes on the mortgage obligation of another party. This means that the new borrower (the party assuming) agrees to take responsibility for the mortgage payments and adheres to the terms of the mortgage contract originally created by the mortgagor (the original borrower).

Assumption is key in real estate transactions, especially when a buyer purchases a property with an existing mortgage. Understanding this concept is essential for recognizing how ownership and financial responsibility can be transferred without the need to pay off the existing debt immediately.

The other options do not accurately describe the act in question. A transfer of mortgage refers to the change in property ownership along with the mortgage but does not specifically imply the taking over of the mortgage obligation itself. An assignment generally pertains to transferring rights under a contract rather than the obligations. Delegation typically means appointing another party to carry out specific tasks but does not involve taking on the financial responsibilities of a mortgage directly.