Why arc records being updated with data that violates the validation rule?

The support operations team has noticed some Invalid data In the custom Primary issue picklist field on case records. They are unsure of what the issue is since the field is being updated by an automated procedure and there Is a validation rule to ensure clean data on case records.

Why arc records being updated with data that violates the validation rule?
A . The data change Is triggered by an update record Flow element.
B . The field is being updated by a workflow field update.
C . The field is being updated by an Apex before trigger.
D . The user has the Modify All Data permission on the object.

Answer: B