Which circumstances will allow SUM to run without the creation of a shadow system? Please choose the correct answer.

Which circumstances will allow SUM to run without the creation of a shadow system? Please choose the correct answer.
A . Using the main configuration option "Single System" when installing an Add-On
B . Using the main configuration option "Single System" in case of an upgrade.
C . Using the database migration option (DMO) for SUM
D . Using the main configuration option "Standard" when applying SAP Support Packages

Answer: A