Which of the following mortgage types allows multiple pieces of property to secure one loan?

A blanket mortgage is specifically designed to allow multiple pieces of property to be secured under a single loan. This type of financing is often used by developers who are purchasing multiple parcels of land or by investors who want to leverage several properties as collateral for one mortgage. It can simplify the financing process because it consolidates multiple loans into one, which can lead to easier management of payments and potentially lower interest rates.

In contrast, an adjustable-rate mortgage involves interest rates that vary over time, and while it pertains to a single property, it does not allow for multiple properties to be included under a single loan. A home equity line of credit allows borrowers to tap into their home equity but does not secure multiple properties under one loan. Lastly, a secondary mortgage typically refers to a second loan taken out on a property, which is also secured by just that particular property rather than multiple properties. Therefore, a blanket mortgage is the clear choice for securing multiple pieces of property under one loan.