What challenges did Stevenson face while trying to defend Walter McMillian?

The choice that highlights the challenges Stevenson faced while defending Walter McMillian accurately encompasses the systemic issues present in McMillian's case. There was substantial evidence showing McMillian's innocence, yet this overwhelming proof was largely ignored by the legal system, revealing deep-seated racism and bias in the process. Racist attitudes permeated the interactions between McMillian, Stevenson, and the local judicial system, complicating the pursuit of justice for McMillian, who was wrongfully convicted due in part to a flawed process rooted in prejudice.

Additionally, the legal system itself proved to be obstructive. This included everything from access to evidence and witnesses to legal representation, as well as the reluctance of key figures to confront the injustices and take action toward rectifying the situation. Those challenges illustrate the broader themes in "Just Mercy," where the struggle for justice is often hindered by institutional barriers that are compounded by racism and societal indifference. Overall, this choice encapsulates the multi-layered obstacles Stevenson encountered, making it the most accurate answer regarding the challenges faced during his defense of McMillian.