Final answer:
An estoppel certificate is a legal document used in real estate transactions to confirm certain facts about a property.
Step-by-step explanation:
An estoppel certificate is a legal document that is often used in real estate transactions. It is a statement signed by a party confirming certain facts about a property. An estoppel certificate typically includes information about the unpaid balance and interest rate on a mortgage, any defects in the title, and other important details related to the property.
Therefore, option d. 'Any defects in the title' is the correct answer. An estoppel certificate is used to confirm the title status of a property, and it is important for buyers and lenders to have accurate information about any defects in the title before proceeding with a transaction.