What does it mean if the Object Fail Threshold is set to 10?

A.
Only send and e-mail for the first 10 objects that fail.

B.
If more than 10 objects fail per migration batch then generate an e-mail.

C.
If more than 10 objects fail to migrate in 24 hours then an e-mail will be sent.

D.
If more than 10 objects across all migration batches fail then an e-mail will be sent.