List the last name of the owner owning the youngest dog.
SELECT T1.last_name FROM Owners AS T1 JOIN Dogs AS T2 ON T1.owner_id  =  T2.owner_id WHERE T2.age  =  ( SELECT max(age) FROM Dogs )
SELECT T1.last_name FROM Owners AS T1 JOIN Dogs AS T2 ON T1.owner_id  =  T2.owner_id WHERE T2.age  =  ( SELECT max(age) FROM Dogs )
[{'last_name': 'Feil'}, {'last_name': 'Fisher'}, {'last_name': 'Rippin'}]