CREATE TABLE table_73555 ("No. in series" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "U.S. viewers  ( in millions ) " TEXT)

What is the title when 2.50 is u.s. viewers (in millions)?
SELECT "Title" FROM table_73555 WHERE "U.S. viewers (in millions)" = '2.50'
SELECT "Title" FROM "table_73555" WHERE "U.S. viewers (in millions)" = '2.50'