In the Xanadian tax system, there is only one tax, on annual personal income. The system is simple: the poorest residents pay no taxes, while middle and upper income residents all pay at the same tax rate of 10% of annual income. Which of the following statement(s) are both true and possible to deduce from the information given? (CHOOSE ALL THAT APPLY)

A. The Xanadian tax system is consistent with the benefits principle.

B. The Xanadian tax system is consistent with the ability-to-pay principle

C. The Xanadian tax system, overall, is proportional.

D. The Xanadian tax system, overall, is progressive