An ArcMap user received new cadastral data to load into an existing feature class, but the attribute fields differ. Which tool can be used to load the data with field mapping?

The Append tool, when set to the schema type NO_TEST, allows a user to load new data into an existing feature class while addressing differences in the attribute fields. This option is especially useful when you want to transfer data with varying schema structures without validating the schema against the destination feature class. By using the NO_TEST setting, you instruct ArcGIS to disregard the schema difference, enabling the import of features from the new data source into the existing feature class based solely on the mapping defined during the operation.

In contrast, the other options do not adequately facilitate the loading of data with differing attribute structures. The simple Data Loader tool with the Schema Only option focuses on creating an empty feature class without transferring actual data, while the import Data tool does not exist in this context. The object Loader's Schema Only option similarly would not allow data transfer but only schema creation without preservation of feature data. Thus, the Append tool with NO_TEST is the most suitable choice for integrating the new cadastral data effectively while managing field mapping challenges.