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: online is a content descriptor of what video game rating system? 
Knowledge Triplets: Pan European Game Information, cvg.computer_game_rating_system.content_descriptors, Discrimination
Online, cvg.computer_game_content_descriptor.versions_with_this_descriptor, m.07xgghn
Sex, cvg.computer_game_content_descriptor.rating_system, Pan European Game Information
Pan European Game Information, cvg.computer_game_rating_system.ratings, 18
m.07xgghn, cvg.computer_game_evaluation.content_descriptors, Online
Pan European Game Information, cvg.computer_game_rating_system.ratings, 7
m.0qx2cg_, dataworld.gardening_hint.last_referenced_by, Pan European Game Information
Pan European Game Information, cvg.computer_game_rating_system.ratings, 16
Violence, cvg.computer_game_content_descriptor.rating_system, Pan European Game Information
Pan European Game Information, cvg.computer_game_rating_system.content_descriptors, Sex
Pan European Game Information, base.schemastaging.context_name.pronunciation, g.125_p1_s3
Drugs, cvg.computer_game_content_descriptor.rating_system, Pan European Game Information
7, cvg.computer_game_rating.rating_system, Pan European Game Information
Pan European Game Information, cvg.computer_game_rating_system.content_descriptors, Fear
Pan European Game Information, cvg.computer_game_rating_system.content_descriptors, Gambling
m.07xgghn, cvg.computer_game_evaluation.rating, 16
m.07xgghn, cvg.computer_game_evaluation.release_rated, NHL 2K10
16, cvg.computer_game_rating.versions_with_this_rating, m.07xgghn
Fear, cvg.computer_game_content_descriptor.rating_system, Pan European Game Information
12, cvg.computer_game_rating.rating_system, Pan European Game Information
Bad language, cvg.computer_game_content_descriptor.rating_system, Pan European Game Information
Pan European Game Information, user.avh.default_domain.ellerdale_topic.ellerdale_id, 0083-65b4
Pan European Game Information, cvg.computer_game_rating_system.ratings, 12
Pan European Game Information, cvg.computer_game_rating_system.content_descriptors, Bad language
Pan European Game Information, cvg.computer_game_rating_system.content_descriptors, Online
3, cvg.computer_game_rating.rating_system, Pan European Game Information
Gambling, cvg.computer_game_content_descriptor.rating_system, Pan European Game Information
NHL 2K10, cvg.game_version.rating, m.07xgghn
Violence, cvg.computer_game_content_descriptor.versions_with_this_descriptor, m.07xgghn
Pan European Game Information, cvg.computer_game_rating_system.content_descriptors, Violence
Discrimination, cvg.computer_game_content_descriptor.rating_system, Pan European Game Information
Pan European Game Information, cvg.computer_game_rating_system.ratings, 3
16, cvg.computer_game_rating.rating_system, Pan European Game Information
Pan European Game Information, cvg.computer_game_rating_system.content_descriptors, Drugs
Online, cvg.computer_game_content_descriptor.rating_system, Pan European Game Information
18, cvg.computer_game_rating.rating_system, Pan European Game Information
m.07xgghn, cvg.computer_game_evaluation.content_descriptors, Violence

Answer: Pan European Game Information