Final answer:
In a warranty deed, the grantor makes several promises, including being the rightful owner, transferring clear title, and defending against other claims on the title.
Step-by-step explanation:
The promise inherently made by a grantor in a warranty deed involves multiple assurances, of which being the rightful owner of the property is one. Specifically, the grantor promises to be the rightful owner of the property, to transfer title to the property without encumbrances, and to defend the title against claims by others. It is worth noting that, although paying off any outstanding debts on the property is often a part of the process in clearing title, the warranty deed itself is primarily concerned with affirming the status of the title and the grantor's right to transfer it.