When can a user become an owner of a record without being a record creator?

When can a user become an owner of a record without being a record creator?

Choose 2 answers.
A . If the record is in a queue
B . If person is above the owner of the record in role hierarchy
C . If he is already a record owner
D . if someone shares the record to the record owner

Answer: A,B

Explanation:

See also: https://help.salesforce.com/apex/HTViewHelpDoc?id=queues_overview.htm&language=enhttps://help.salesforce.com/apex/HTViewHelpDoc?id=data_about_transfer.htm&langu age=en