CREATE TABLE table_52308 ("Call sign" CLOB, "Frequency MHz" FLOAT, "City of license" CLOB, "ERP W" FLOAT, "Class" CLOB, "FCC info" CLOB)

What is the call sign for a class of A?
SELECT "Call sign" FROM table_52308 WHERE "Class" = 'a'
SELECT "Call sign" FROM "table_52308" WHERE "Class" = 'a'