In the context of digital design, particularly when developing a user interface for a new app, authenticity is important for several reasons. Among the given options, the most relevant is:
It prevents legal issues related to copyright infringement.
This is because creating original designs and content helps to avoid potential legal problems that can arise from using copyrighted material without permission. However, it is worth noting that while authenticity can also contribute to user trust and brand loyalty, which might indirectly lead to attracting a larger audience, the protection against legal issues is a more direct reason tied to the concept of authenticity in design.
If you have to choose only one response from the options provided, the best fit that directly addresses the importance of authenticity is the prevention of legal issues related to copyright infringement.