When is an ArcGlS user required to change the format of data before working with it in ArcMap?

When is an ArcGlS user required to change the format of data before working with it in ArcMap?
A . when the data is an ESRI interchange (.e00) file
B . when the data is an Autodesk dwg file
C . when the data is an ERDAS Imagine (img) file
D . when the data is in a JPEG (jpg) format

Answer: A