What is the Callsign in Brisbane with a Freq currently of 4rph?
CREATE TABLE table_name_52 (
    callsign VARCHAR,
    area_served VARCHAR,
    freq_currently VARCHAR
)
SELECT callsign FROM table_name_52 WHERE area_served = "brisbane" AND freq_currently = "4rph"
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: What is the Callsign in Brisbane with a Freq currently of 4rph? ### Input: CREATE TABLE table_name_52 (
    callsign VARCHAR,
    area_served VARCHAR,
    freq_currently VARCHAR
) ### Response: SELECT callsign FROM table_name_52 WHERE area_served = "brisbane" AND freq_currently = "4rph"