CREATE TABLE table_17759 ("No." FLOAT, "Title" CLOB, "Directed by" CLOB, "Written by" CLOB, "Bens location" CLOB, "Original air date" CLOB, "U.S. viewers  ( million ) " CLOB)

What was the original air date for the episode with 3.90 u.s. viewers (millions)?
SELECT "Original air date" FROM table_17759 WHERE "U.S. viewers (million)" = '3.90'
SELECT "Original air date" FROM "table_17759" WHERE "U.S. viewers (million)" = '3.90'