Question: who plays joker in batman the dark knight
[{'answer': 'Ledger', 'provenance': [{'wikipedia_id': '17173785', 'title': 'Heath Ledger', 'start_paragraph_id': 0, 'start_character': 6, 'end_paragraph_id': 0, 'end_character': 12, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '17173785', 'title': 'Heath Ledger', 'start_paragraph_id': 3, 'start_character': 38, 'end_paragraph_id': 3, 'end_character': 1036, 'bleu_score': 0.6512853165447471, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15618221446945608811}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '17173785', 'title': 'Heath Ledger', 'start_paragraph_id': 13, 'start_character': 0, 'end_paragraph_id': 13, 'end_character': 1079, 'bleu_score': 0.9190355522219751, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15618221446945608811}, 'section': 'Section::::Career.:2000s.\n'}]}, {'provenance': [{'wikipedia_id': '21145395', 'title': 'Joker (The Dark Knight)', 'section': 'Section::::Reception and legacy.:Critical reception.\n', 'start_paragraph_id': 43, 'end_paragraph_id': 43, 'meta': {'evidence_span': ['the casting felt "just about right. I eagerly anticipate more!" Heath Ledger\'s portrayal of the Joker received critical acclaim, winning numerous posthumous awards for his performance, including the Academy Award for Best Supporting Actor, a Golden Globe Award for Best Supporting Actor in a Motion Picture, the BAFTA Award for Best Actor in a Supporting Role, the Saturn Award for Best Supporting Actor, a Screen Actors Guild Award for Outstanding Performance by a Male Actor in a Supporting Role, and a Best Actor International Award at the 2008 Australian Film Institute Awards.\rhighlight sentence(s) containing evidence, not only the answer', "Heath Ledger's portrayal of the Joker received critical acclaim", 'the casting felt "just about right. I eagerly anticipate more!" Heath Ledger\'s portrayal of the Joker received critical acclaim, winning numerous posthumous awards for his performance,']}}]}, {'provenance': [{'wikipedia_id': '4276475', 'title': 'The Dark Knight (film)', 'section': 'Section::::Reception.\n', 'start_paragraph_id': 61, 'end_paragraph_id': 61, 'meta': {'evidence_span': ['The Dark Knight" was ranked the 15th greatest film in history on "Empire"s 2008 list of the "500 Greatest Movies of All Time," based upon the weighted votes of 10,000 readers, 150 film directors, and 50 key film critics. Heath Ledger\'s interpretation of the Joker was also ranked number three on "Empire"s 2008 list of the "100 Greatest Movie Characters of All Time."', 'Heath Ledger\'s interpretation of the Joker was also ranked number three on "Empire"s 2008 list of the "100 Greatest Movie Characters of All Time."', 'Heath Ledger\'s interpretation of the Joker was also ranked number three on "Empire"s 2008 list of the "100 Greatest Movie Characters of All Time.']}}]}, {'provenance': [{'wikipedia_id': '98301', 'title': 'Joker (character)', 'section': 'Section::::Cultural impact and legacy.:In other media.\n', 'start_paragraph_id': 76, 'end_paragraph_id': 76, 'meta': {'evidence_span': ['After Christopher Nolan\'s successful 2005 Batman film reboot, "Batman Begins", which ended with a teaser for the Joker\'s involvement in a sequel, the character appeared in 2008\'s "The Dark Knight", played by Heath Ledger as an avatar of anarchy and chaos. While "Batman Begins" earned a worldwide total of $370\xa0million; "The Dark Knight" earned over $1\xa0billion and was the highest-grossing film of the year, setting several box-office records (including highest-grossing midnight opening, opening day and opening weekend).', 'After Christopher Nolan\'s successful 2005 Batman film reboot, "Batman Begins", which ended with a teaser for the Joker\'s involvement in a sequel, the character appeared in 2008\'s "The Dark Knight", played by Heath Ledger as an avatar of anarchy and chaos.']}}]}]