Question: who played tammy on the tv show mom
[{'answer': 'Kristen Johnston', 'provenance': [{'wikipedia_id': '55071463', 'title': 'Mom (season 5)', 'start_paragraph_id': 28, 'start_character': 12, 'end_paragraph_id': 28, 'end_character': 28, 'bleu_score': 1.0, 'section': 'Section::::Cast.:Special guest stars.\n'}]}, {'provenance': [{'wikipedia_id': '55071463', 'title': 'Mom (season 5)', 'start_paragraph_id': 28, 'start_character': 0, 'end_paragraph_id': 28, 'end_character': 48, 'bleu_score': 0.6147881529512641, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11805296911290565954}, 'section': 'Section::::Cast.:Special guest stars.\n'}]}]