Part of the Problem with the Onity Lock Hotel Thefts

Part of the problem with the Onity lock hotel thefts is that although the problem was identified and presented at the Black Hat conference, Onity was unable to correct the issue _____________.

A) because they had not included any update mechanism for the locks.
B) because Cashatt and Brocious had already reprogrammed the locks, essentially locking Onity out of their own software.
C) because there was no way of tracking which locks were compromised.
D) because the hotels that utilized the locks had not maintained software updates.