What does this mean?

A user has created a custom metadata schema that includes a multi value text field. After modifying the file that the metadata has been applied to, the user discovers that the property corresponding to the multi value text field contains a new value.

What does this mean?
A . Another metadata schema that was previously applied to the asset is causing a conflict.
B . The multi value text field was simultaneously updated by a different AEM Assets user.
C . The multi value text field is configured as a required field in the metadata schema.
D . Another field in the metadata schema maps to the same property as the multi value text field.

Answer: A