human
Considering the provided database schema and associated query, produce SQL code to retrieve the answer to the query. 
###Database Schema: No. in series, No. in season, Title, Directed by, Written by, Original air date, Prod. code, U.S. viewers (millions)
###Question: who directed the episode that 6.3 million u.s. viewers saw?
gpt
SELECT Directed by FROM table WHERE U.S. viewers (millions) = 6.3