CREATE TABLE table_79789 ("Call sign" CLOB, "Frequency" CLOB, "City of license" CLOB, "Facility ID" FLOAT, "ERP / Power W" FLOAT, "Height m  (  ft  ) " CLOB, "Class" CLOB, "FCC info" CLOB)

What city has the A Class licence?
SELECT "City of license" FROM table_79789 WHERE "Class" = 'a'
SELECT "City of license" FROM "table_79789" WHERE "Class" = 'a'