The primary criticism from some in the US, Britain, and France regarding the Nuremberg Trials can be summarized as:
A) they considered the trials victors' justice lacking legal authority.
Many critics argued that the trials were a form of "victor's justice," where the winners of the war were putting the losers on trial without legal precedent or a fair process. They were concerned about the legitimacy and fairness of the trials, believing it set a dangerous precedent for international law.
While some may have had varying reasons for their criticism, option A encompasses the core concern about the legal and ethical foundations of the trials.