Question: What is the name of the American game designer who co-developed Dungeons & Dragons Basic Set and who developed the concept of the RPG?
{'answer': 'Dave Arneson', 'supporting_facts': [['Dungeons &amp; Dragons Basic Set', 0], ['Dungeons &amp; Dragons Basic Set', 1], ['Dungeons &amp; Dragons Basic Set', 2], ['Dave Arneson', 0]]}