Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE Owners (owner_id VARCHAR, last_name VARCHAR)
TABLE: CREATE TABLE Dogs (owner_id VARCHAR, dog_id VARCHAR)
TABLE: CREATE TABLE Treatments (dog_id VARCHAR)

### Question ###
Which owner has paid for the most treatments on his or her dogs? List the owner id and last name.

### Accurate SQL ###

SELECT T1.owner_id, T1.last_name FROM Owners AS T1 JOIN Dogs AS T2 ON T1.owner_id = T2.owner_id JOIN Treatments AS T3 ON T2.dog_id = T3.dog_id GROUP BY T1.owner_id ORDER BY COUNT(*) DESC LIMIT 1