A developer placed a mortgage on his housing development. The mortgage the developer obtained was:

The most suitable answer in this context is a blanket mortgage. A blanket mortgage is specifically designed for developers or builders who finance multiple properties under one loan. This type of mortgage allows the developer to secure funding for an entire subdivision or housing development rather than requiring separate financing for each individual property.

This arrangement offers several advantages, such as simplifying the financing process and potentially enabling lower interest rates due to the larger loan amount. Developers often use blanket mortgages because they allow for the properties to be sold off individually while still securing the entire development under one mortgage, which provides flexibility in managing the project.

A partial mortgage refers to a loan covering a portion of a property's value, which does not align with the context of a developer financing multiple properties. A secured mortgage simply means the loan is backed by collateral (the property), but this term is too broad. A conventional mortgage typically pertains to loans that follow the guidelines set by Fannie Mae or Freddie Mac and may not specifically relate to developers financing multiple lots or buildings. Thus, the notion of a blanket mortgage fits best in this scenario.