The statement that accurately compares public debt to intragovernmental debt is:
Public debt is securities issued by the Treasury to investors while intragovernmental debt are loans within the federal government from the excess funds of other agencies.
This statement correctly describes public debt as the portion of the national debt that is held by the public through securities, and it explains intragovernmental debt as the portion of the debt held by various government accounts, like trust funds, which lend excess funds to one another.