Under the Fourteenth Amendment Rights, when may the government impose a substantial burden on a prisoner's religious exercise?

The rationale for the correct choice lies in the established legal framework surrounding religious freedoms and prisoners' rights, particularly as articulated in the Religious Land Use and Institutionalized Persons Act (RLUIPA) and subsequent court interpretations related to the Fourteenth Amendment.

Under the Fourteenth Amendment, a substantial burden on a prisoner's religious exercise is permissible only if there is a compelling government interest. This means that if the government wishes to limit a prisoner's free exercise of religion, it must demonstrate that its action is necessary to achieve a significant governmental goal that cannot be accomplished by less restrictive means. Such compelling interests may include ensuring security within the prison, preventing violence, or maintaining order.

This principle is grounded in the need to balance the rights of individuals to practice their religion against the legitimate interests of the state in maintaining safety and order within correctional facilities. Therefore, under this legal framework, the government's interest must be significant and supported by evidence that justifies infringing on a prisoner's religious practices.