user: Question: What is the Series of the Filmography with a Production Number of M-4-15?
Columns: ['Title', 'Series', 'Director', 'Production Number', 'Release date']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Book Revue', 'LT', 'Bob Clampett', '8-15, BR 1234', '1946-01-05']
SQL:

assistant: SELECT "Series" FROM "Table" WHERE "Production Number" = 'M-4-15';