Question: what grade was arnold from hey arnold in
[{'answer': 'fourth', 'provenance': [{'wikipedia_id': '206490', 'title': 'Hey Arnold!', 'start_paragraph_id': 1, 'start_character': 178, 'end_paragraph_id': 1, 'end_character': 184, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '206490', 'title': 'Hey Arnold!', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 391, 'bleu_score': 0.944371605316466, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4062265908738206973}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '13509520', 'title': 'Jamil Walker Smith', 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ['His best known role is as the voice of Gerald, a fourth grader and Arnold\'s best friend in the Nickelodeon TV series "Hey Arnold!". He also appeared on various shows like "Sister, Sister"; "Girlfriends"; "Bones"; "The X-Files"; and "The Bernie Mac Show".', 'fourth', 'His best known role is as the voice of Gerald, a fourth grader and Arnold\'s best friend in the Nickelodeon TV series "Hey Arnold!".']}}]}, {'provenance': [{'wikipedia_id': '5416747', 'title': 'List of Hey Arnold! episodes', 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ['"Hey Arnold!" is an American animated television series created by Craig Bartlett that aired on Nickelodeon from October 7, 1996 to June 8, 2004. The show centers on a fourth grader named Arnold, who lives with his grandparents in an inner-city boarding house.', 'fourth', 'The show centers on a fourth grader named Arnold, who lives with his grandparents in an inner-city boarding house']}}]}, {'provenance': [{'wikipedia_id': '206490', 'title': 'Hey Arnold!', 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ["Hey Arnold! is an American animated children's television series created by Craig Bartlett that aired on Nickelodeon from October 7, 1996, to June 8, 2004. The show centers on a fourth grader named Arnold, who lives with his grandparents in an inner-city boarding house.", 'fourth', "Hey Arnold! is an American animated children's television series created by Craig Bartlett that aired on Nickelodeon from October 7, 1996, to June 8, 2004. The show centers on a fourth grader named Arnold, who lives with his grandparents in an inner-city boarding house."]}}]}]