This information applies to version(s): 1, 2, 3, 4, 5, 6
If multiple optical modules are offered, it means that the imported images have EXIF data that relates to multiple cameras or lenses in our database. This happens when manufacturers don't use unique IDs for their hardware. We offer a selection in such cases so that the appropriate option can be chosen by the user.
For more information see this other article here explaining how DxO associates optical modules to an image, and what are the limitations.