Elan's board game concept would be primarily protected by copyright and potentially by patent if the game has a novel gameplay mechanic or unique processes. Copyright protects the expression of her idea, such as the artwork, rules, and written materials. A patent would protect any specific, novel inventions or methods used within the game. Therefore, to answer the question regarding protection from others using her idea without permission, the most relevant response would be copyright for the overall game expression.
If the question focuses on the legal mechanism that could provide protection against others using her idea conceptually (given that ideas themselves cannot be copyrighted), patent might also be a suitable answer depending on the unique aspects of the game. However, since the specific options are presented, the best overall answer is copyright.