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: frostbite engine was preceded by what video game engine? 
Knowledge Triplets: Frostbite 2, cvg.computer_game_engine.engine_family, Frostbite
Frostbite, cvg.computer_game_engine.used_for_computer_games, Battlefield: Bad Company
Frostbite, computer.software.compatible_oses, m.0w5pjs7
EA Digital Illusions CE, cvg.computer_game_engine_developer.computer_game_engines_developed, Frostbite 2
Frostbite 2, cvg.computer_game_engine.predecessor_engine, Frostbite 1.5
Need for Speed: The Run, cvg.computer_videogame.uses_game_engine, Frostbite 2
Frostbite 1.5, cvg.computer_game_engine.successor_engine, Frostbite 2
Battlefield: Bad Company 2, cvg.computer_videogame.uses_game_engine, Frostbite 1.5
Frostbite, computer.software.license, Proprietary software
Frostbite, cvg.computer_game_engine.developer, EA Digital Illusions CE
Battlefield: Bad Company 2: Vietnam, cvg.computer_videogame.uses_game_engine, Frostbite 1.5
Rory McIlroy PGA Tour, cvg.computer_videogame.uses_game_engine, Frostbite
Mirror's Edge Catalyst, cvg.computer_videogame.uses_game_engine, Frostbite 2
Frostbite, computer.software.software_genre, 3D game engine
Mirror's Edge Catalyst, cvg.computer_videogame.uses_game_engine, Frostbite
Frostbite 1.5, cvg.computer_game_engine.predecessor_engine, Frostbite
Frostbite, cvg.computer_game_engine.used_for_computer_games, Mirror's Edge Catalyst
m.0h50x41, dataworld.gardening_hint.last_referenced_by, Frostbite
Frostbite, cvg.computer_game_engine_family.engines_in_this_family, Frostbite 1.5
Frostbite, cvg.computer_game_engine.engine_family, Frostbite
Dragon Age: Inquisition, cvg.computer_videogame.uses_game_engine, Frostbite
Frostbite 1.5, cvg.computer_game_engine.engine_family, Frostbite
Frostbite, computer.software.software_genre, Game engine
EA Digital Illusions CE, cvg.computer_game_engine_developer.computer_game_engines_developed, Frostbite
Frostbite, cvg.computer_game_engine.used_for_computer_games, Command & Conquer
Frostbite, cvg.computer_game_engine.successor_engine, Frostbite 1.5
Frostbite, cvg.computer_game_engine.used_for_computer_games, Rory McIlroy PGA Tour
Frostbite 2, cvg.computer_game_engine.developer, EA Digital Illusions CE
Frostbite 1.5, cvg.computer_game_engine.used_for_computer_games, Battlefield: Bad Company 2: Vietnam
EA Digital Illusions CE, cvg.computer_game_engine_developer.computer_game_engines_developed, Frostbite 1.5
Game engine, computer.software_genre.software_in_genre, Frostbite
3D game engine, computer.software_genre.software_in_genre, Frostbite
Frostbite, cvg.computer_game_engine_family.engines_in_this_family, Frostbite 2
Frostbite, cvg.computer_game_engine_family.engines_in_this_family, Frostbite
Battlefield: Bad Company, cvg.computer_videogame.uses_game_engine, Frostbite
Frostbite, cvg.computer_game_engine.used_for_computer_games, Dragon Age: Inquisition
Frostbite 2, cvg.computer_game_engine.used_for_computer_games, Mirror's Edge Catalyst
Command & Conquer, cvg.computer_videogame.uses_game_engine, Frostbite
Frostbite 2, cvg.computer_game_engine.used_for_computer_games, Battlefield 3
m.0w5pjs7, computer.software_compatibility.software, Frostbite
Frostbite 1.5, cvg.computer_game_engine.used_for_computer_games, Battlefield 1943
Battlefield 3, cvg.computer_videogame.uses_game_engine, Frostbite 2
Frostbite 2, cvg.computer_game_engine.used_for_computer_games, Need for Speed: The Run
Frostbite 1.5, cvg.computer_game_engine.used_for_computer_games, Battlefield: Bad Company 2
Frostbite 1.5, cvg.computer_game_engine.developer, EA Digital Illusions CE
Battlefield 1943, cvg.computer_videogame.uses_game_engine, Frostbite 1.5

Answer: Frostbite 2
Frostbite 1.5