Final answer:
In the novel "To Kill a Mockingbird," Scout is referring to Jem breaking the code of their childhood by defying the laws, who were his nurturers.
Step-by-step explanation:
In the novel "To Kill a Mockingbird," the violation that causes Scout to make the comment "Then Jem rose and broke the remaining code of our childhood" is b) defying the laws, who were his nurturers. Jem breaks the code of their childhood by disobeying their father's instructions and entering the Radley property. This violation represents a loss of innocence and a departure from their childhood games and fantasies.