Given the task definition and input, reply with output. This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.

Passage: In a career spanning more than four decades, Spielberg's films have covered many themes and genres. Spielberg's early science-fiction and adventure films were seen as archetypes of modern Hollywood blockbuster filmmaking. In later years, his films began addressing humanistic issues such as the Holocaust (in Schindler's List), the transatlantic slave trade (in Amistad), war (in Empire of the Sun, Saving Private Ryan, War Horse and Bridge of Spies) and terrorism (in Munich). His other films include Close Encounters of the Third Kind, the Indiana Jones film series, and A.I. Artificial Intelligence.
What is Spielberg's most critically acclaimed film?