Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_67 (callsign VARCHAR, on_air_id VARCHAR)
### Question:
What is 4zr's callsign?
### Answer:
SELECT callsign FROM table_name_67 WHERE on_air_id = "4zr"