By default, the project files always target the lowest version of the .NET
Framework supported by the associated version of Visual Studio; however,
using the project file properties, this can be overridden.  That is largely
the extent of the support for the .NET Framework 4.7.1 and 4.7.2, which are
largely based on the "TargetFramework" attribute of the managed assemblies.

All that being said, for most use cases, the managed assemblies targeting
the .NET Framework 4.0 should be used instead.