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_50 (purpose VARCHAR, freq_currently VARCHAR, area_served VARCHAR)
### Question:
What is the purpose for the katherine freq of 8rn?
### Answer:
SELECT purpose FROM table_name_50 WHERE freq_currently = "8rn" AND area_served = "katherine"