Explanation:

- Equitable Mortgage: This is when the borrower deposits their title deeds with the lender without a formal, registered document. This is often called a "mortgage by deposit of title deeds."

Correct Answer: Equitable Mortgage

- Simple Mortgage: The borrower personally pledges an express promise to repay the loan. The property itself isn't directly transferred to the lender, but the lender has the right to sell it if repayment fails.

- Usufructuary Mortgage: The lender receives possession of the property and is entitled to income generated by the property (e.g., rent) instead of interest until the loan is repaid.

- Anomalous Mortgage: This type involves elements of different mortgage types and doesn't fit neatly into established categories.