1. Fortinet FortiManager Administration Guide 7.4.1
Page 238
Section: "Moving devices to another ADOM".
The guide states
"When you move a device to another ADOM
a confirmation dialog box is displayed. After you confirm the move
the device is moved to the other ADOM." This directly confirms that the dialog box (Option A) is the immediate output when the action is initiated.
The same section later explains the consequences: "When a device is moved to a new ADOM
the device's configuration is retrieved. The configuration is compared against the new ADOM's database
and the device's configuration status becomes modified." This supports why options B and D are subsequent results
not the initial output.