The Solid Import page contains the following options:
Import PMI — Select this option to import Product Manufacturing Information such as dimensions, annotations, and tolerances when importing Creo, NX, and CatiaV5 files.
Import hidden Catia V5 solids — Select this option to import all parts contained in the CATIA file even if those parts are hidden.
Import file as solids — Select this option to import files as solid models. If this option is deselected, the models are imported as surface models. We recommend that you import models as solids. If this option is selected and the solid fails to import properly, you are asked if you would like to attempt to heal the solid to try and fix the import problem.
Import work planes — When selected, planar surfaces in solids are imported. When deselected, planar surfaces in solids are ignored.
Stitch IGES surfaces into solids/sheets — Select this option to try to create one or more solids or sheets from an IGES file. If an IGES file contains more than one solid or sheet, this is the most efficient way to create the multiple objects from the file.