Final answer:
According to the Sophists, the claim that the only thing that matters is whatever persuades most people best is true. The Sophists believed in the power of persuasion and winning.
Step-by-step explanation:
The claim that according to the Sophists, the only thing that matters is whatever persuades most people best is true. The Sophists were known for their emphasis on rhetoric and persuasion. They believed that truth is subjective and relative, and that winning and succeeding are the ultimate goals. This can be seen in their teachings and in their emphasis on skills such as rhetoric and persuasion.