Question: who plays the doc in back to the future
[{'answer': 'Christopher Allen Lloyd', 'provenance': [{'wikipedia_id': '256406', 'title': 'Christopher Lloyd', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 23, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '256406', 'title': 'Christopher Lloyd', 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ['Lloyd also starred as Emmett "Doc" Brown in the "Back to the Future" trilogy, Judge Doom in "Who Framed Roger Rabbit" (1988),', 'Christopher Allen Lloyd (born October 22, 1938) is an American actor and voice actor. Lloyd came to public attention in Northeastern theater productions during the 1960s and early 1970s, earning Drama Desk and Obie awards for his work. He made his screen debut in "One Flew Over the Cuckoo\'s Nest" (1975), and gained widespread recognition as Jim Ignatowski in the comedy series "Taxi" (19781983), for which he won two Emmy Awards', 'Lloyd also starred as Emmett "Doc" Brown in the "Back to the Future" trilogy, J']}}]}, {'provenance': [{'wikipedia_id': '1448656', 'title': 'Back to the Future (TV series)', 'section': 'Section::::Intro.\n', 'start_paragraph_id': 8, 'end_paragraph_id': 8, 'meta': {'evidence_span': ["They subsequently find him driving the steam train time machine to an unknown time. For the second season, the intro replaces the collection of the main characters with clips of the first season and ends with the same sequence from season one's intro. Mary Steenburgen (Clara Clayton Brown) and Thomas F. Wilson (Biff Tannen) voiced their characters from the films. Christopher Lloyd played Doc Brown", 'Christopher Lloyd played Doc Brown in']}}]}, {'provenance': [{'wikipedia_id': '5299314', 'title': 'List of Back to the Future characters', 'section': 'Section::::Main characters.:Marty McFly.\n', 'start_paragraph_id': 5, 'end_paragraph_id': 5, 'meta': {'evidence_span': ['Marty travels between the past and the future, encountering his ancestors and descendants. Marty and his friend Doc Brown help restore the space-time continuum while encountering Biff Tannen (or members of the Tannen clan) at various points in time. Doctor Emmett Lathrop "Doc" Brown (portrayed by Christopher Lloyd in the films and "Back to the Future:', 'Doctor Emmett Lathrop "Doc" Brown (portrayed by Christopher Lloyd in the films and "Back to the Future:']}}]}]