Table schema:
CREATE TABLE Owners (last_name VARCHAR, owner_id VARCHAR); CREATE TABLE Dogs (owner_id VARCHAR, age INTEGER); CREATE TABLE Dogs (age INTEGER)

Question: List the last name of the owner owning the youngest dog.
SQL: 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)