CREATE TABLE table_73840 ("Series #" FLOAT, "Season #" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "Production code" TEXT, "U.S. viewers  ( million ) " TEXT)

Who directed the episode with production code ca311?
SELECT "Directed by" FROM table_73840 WHERE "Production code" = 'CA311'
SELECT "Directed by" FROM "table_73840" WHERE "Production code" = 'CA311'