Final answer:
The concession in "Reality is Broken" serves to show that the author rebutts the claim that historical events never repeat, allowing her to utilize history to predict future gaming trends and confront the potential for unexpected outcomes.
Step-by-step explanation:
The underlined concession in the excerpt from "Reality is Broken" can show that McGonigal acknowledges the viewpoint that historical events do not repeat exactly, which allows her to make a strong counter-argument about the value of understanding historical patterns when predicting the future.
This perspective enables her to demonstrate her comprehensive grasp on the subject and allows for a more nuanced argument regarding the potential utility of game history for future predictions. By referencing past behavioral patterns and their influence on the present, McGonigal uses the study of history and its impact on human behavior to support her main argument that history can inform future trends in gaming and broader implications.
In this context, the concession falls under option c, It allows the author to rebut the claim that historical events are never repeated. This strategic acknowledgement supports the book's core message, which considers the history of gameplay to understand and influence future outcomes.