CREATE TABLE table_14591 ("Res." TEXT, "Record" TEXT, "Opponent" TEXT, "Method" TEXT, "Event" TEXT, "Round" FLOAT, "Time" TEXT, "Location" TEXT)

Which Opponent has a Method of submission?
SELECT "Opponent" FROM table_14591 WHERE "Method" = 'submission'
SELECT "Opponent" FROM "table_14591" WHERE "Method" = 'submission'