CREATE TABLE table_43222 ("Card" TEXT, "Weight Class" TEXT, "Round" FLOAT, "Time" TEXT, "Method" TEXT)

Which method was used in the welterweight class with a preliminary card?
SELECT "Method" FROM table_43222 WHERE "Weight Class" = 'welterweight' AND "Card" = 'preliminary'
SELECT "Method" FROM "table_43222" WHERE "Card" = 'preliminary' AND "Weight Class" = 'welterweight'