user: You are a structured reasoning expert tasked with solving problems step by step. 
You first think about the reasoning process in the mind and then provide the answer. The reasoning process and answer should be enclosed within <think> </think> and <answer> </answer> tags, respectively, i.e., <think> reasoning process here </think> <answer> answer here </answer>. 
Given a question and the associated knowledge graph triplets (entity, relation, entity), you are asked to answer the question with these triplets and your own knowledge. 
You can break down the original question into several sub-questions and explore the given knowledge graph to solve them step-by-step. If there are multiple possible answers, choose one as the final answer. 
After thinking, when you finally reach a conclusion, clearly state the answer within <answer> </answer> tags, i.e., <answer> answer here </answer>. 
Question: bell 206b is of what model line? 
Knowledge Triplets: Bell 206, aviation.aircraft_model.variants, Bell 407
Agusta-Bell 206L, aviation.aircraft_model.part_of_line, Bell 206
Agusta-Bell 206L-3, aviation.aircraft_model.part_of_line, Bell 206
Bell 206, aviation.aircraft_line.models_in_line, Bell 206L-1 LongRanger II
Bell 206, aviation.aircraft_line.models_in_line, Bell 206L LongRanger
Bell 206, aviation.aircraft_model.cruise_speed, 219.0
Bell 206, aviation.aircraft_line.models_in_line, Bell 206A
Bell 206, aviation.aircraft_line.models_in_line, Bell 206L-3+ LongRanger
Bell 206, aviation.aircraft_line.models_in_line, 206L TexasRanger
Bell 206, aviation.aircraft_model.part_of_line, Bell 206
Bell 407, aviation.aircraft_model.parent_aircraft_model, Bell 206
Bell 206, aviation.aircraft_line.models_in_line, Bell 206B
Agusta-Bell 206A, aviation.aircraft_model.part_of_line, Bell 206
Bell 206, aviation.aircraft_line.models_in_line, Bell 206LT TwinRanger
Bell 407, aviation.aircraft_model.part_of_line, Bell 206
Bell 206L LongRanger, aviation.aircraft_model.part_of_line, Bell 206
Bell 206, aviation.aircraft_line.models_in_line, Bell 417
Bell 206, aviation.aircraft_line.models_in_line, Agusta-Bell 206A
Bell 206, user.avh.default_domain.ellerdale_topic.ellerdale_id, 0083-5b38
Bell 417, aviation.aircraft_model.part_of_line, Bell 206
Bell 206, aviation.aircraft_line.models_in_line, Bell CH-139 JetRanger
TH-57C, aviation.aircraft_model.part_of_line, Bell 206
Bell 206, aviation.aircraft_line.models_in_line, Bell 206AS
Bell 206A, aviation.aircraft_model.part_of_line, Bell 206
Bell 206, aviation.aircraft_line.models_in_line, TH-57B
TH-57A, aviation.aircraft_model.part_of_line, Bell 206
Bell 206, aviation.aircraft_model.variants, HESA Shahed 285
Bell 206AS, aviation.aircraft_model.part_of_line, Bell 206
m.0n1srwz, aviation.comparable_aircraft_relationship.aircraft, Bell 206
Bell 206, aviation.aircraft_model.passengers, m.0x0jjh4
Bell 206, aviation.aircraft_line.models_in_line, Bell 206B-3
Bell 206, aviation.aircraft_line.models_in_line, Bell 206L-3 LongRanger III
Bell 206L-1+ LongRanger, aviation.aircraft_model.part_of_line, Bell 206
Bell CH-139 JetRanger, aviation.aircraft_model.part_of_line, Bell 206
Bell 206, aviation.aircraft_model.comparable_aircraft, m.0pkp20g
Bell 206, base.schemastaging.aircraft_model_extra.manufacturers_empty_weight, 718.0
TH-57B, aviation.aircraft_model.part_of_line, Bell 206
Bell 206, aviation.aircraft_line.models_in_line, TH-57C
Bell 400, aviation.aircraft_model.parent_aircraft_model, Bell 206
HESA Shahed 278, aviation.aircraft_model.parent_aircraft_model, Bell 206
Bell 206, aviation.aircraft_model.length_meters, 12.09
Agusta-Bell 206B, aviation.aircraft_model.part_of_line, Bell 206
Bell 206, aviation.aircraft_line.models_in_line, TH-57A
Bell 206, aviation.aircraft_line.models_in_line, TH-67 Creek
Bell 206, aviation.aircraft_line.models_in_line, Bell 206A-1
TH-67 Creek, aviation.aircraft_model.part_of_line, Bell 206
Bell 206, aviation.aircraft_line.models_in_line, Bell 206L-4 LongRanger IV
Bell 206, aviation.aircraft_line.models_in_line, Bell 206B-2
TH-57D, aviation.aircraft_model.part_of_line, Bell 206
Bell 206, aviation.aircraft_line.models_in_line, TH-57D
HESA Shahed 285, aviation.aircraft_model.parent_aircraft_model, Bell 206
Bell 206L-1 LongRanger II, aviation.aircraft_model.part_of_line, Bell 206
Bell 206, aviation.aircraft_line.models_in_line, Bell 206
Agusta-Bell 206A-1, aviation.aircraft_model.part_of_line, Bell 206
Bell 206, aviation.aircraft_model.variants, Bell 400
Agusta-Bell 206L-1, aviation.aircraft_model.part_of_line, Bell 206
Bell 206LT TwinRanger, aviation.aircraft_model.part_of_line, Bell 206
Bell 206, aviation.aircraft_model.range, 702.0
Bell 206, aviation.aircraft_line.models_in_line, Agusta-Bell 206L-1
Bell 206, aviation.aircraft_model.variants, HESA Shahed 278
Bell 206, aviation.aircraft_model.engine_type, Allison Model 250
Bell 206, aviation.aircraft_model.comparable_aircraft, m.0n1srwz
Bell 206L-4 LongRanger IV, aviation.aircraft_model.part_of_line, Bell 206
Bell 206B-3, aviation.aircraft_model.part_of_line, Bell 206
Bell 206L-3 LongRanger III, aviation.aircraft_model.part_of_line, Bell 206
Bell 206, aviation.aircraft_line.models_in_line, Agusta-Bell 206A-1
Bell 206, aviation.aircraft_model.manufacturer, Bell Helicopter
m.0r1zb3h, dataworld.gardening_hint.last_referenced_by, Bell 206
Bell 206, aviation.aircraft_line.models_in_line, Agusta-Bell 206L
Bell 206, aviation.aircraft_model.variants, Panha Shabaviz 206-1
Bell 206B-2, aviation.aircraft_model.part_of_line, Bell 206
Bell 206, aviation.aircraft_model.maximum_speed_km_h, 222.2
Bell 206, aviation.aircraft_line.models_in_line, Agusta-Bell 206B
Bell Helicopter, aviation.aircraft_manufacturer.aircraft_models_made, Bell 206
206L TexasRanger, aviation.aircraft_model.part_of_line, Bell 206
Bell 206, aviation.aircraft_line.models_in_line, Bell 206L-1+ LongRanger
Panha Shabaviz 206-1, aviation.aircraft_model.parent_aircraft_model, Bell 206
Bell 206, aviation.aircraft_line.models_in_line, Bell 407
Bell 206B, aviation.aircraft_model.part_of_line, Bell 206
Bell 206A-1, aviation.aircraft_model.part_of_line, Bell 206
m.0pkp20g, aviation.comparable_aircraft_relationship.aircraft, Bell 206
Bell 206, aviation.aircraft_model.unit_cost, m.0x0jh9k
Bell 206B, aviation.aircraft_line.models_in_line, Bell 206
Bell 206, aviation.aircraft_line.models_in_line, Agusta-Bell 206L-3
Bell 206, aviation.aircraft_model.wingspan, 10.16
Bell 206L-3+ LongRanger, aviation.aircraft_model.part_of_line, Bell 206

Answer: Bell 206