CREATE TABLE table_name_56 (primary_conference VARCHAR, ihsaa_football_class VARCHAR, school VARCHAR)

What is the primary conference with a IHSAA Football Class of A, at South Decatur school?
SELECT primary_conference FROM table_name_56 WHERE ihsaa_football_class = "a" AND school = "south decatur"
SELECT "primary_conference" FROM "table_name_56" WHERE "a" = "ihsaa_football_class" AND "school" = "south decatur"