CREATE TABLE table_19155 ("High School" TEXT, "Type" TEXT, "Established" FLOAT, "Enrollment" FLOAT, "Mascot" TEXT, "WIAA Classification" TEXT, "Notes" TEXT)

What is the WIAA classification of Oakland Alternative High School?
SELECT "WIAA Classification" FROM table_19155 WHERE "High School" = 'Oakland Alternative'
SELECT "WIAA Classification" FROM "table_19155" WHERE "High School" = 'Oakland Alternative'