What entity has the authority to change the boundaries of the state of Arizona?

The authority to change the boundaries of the state of Arizona lies with Congress. This power is established by the U.S. Constitution, which gives Congress the authority to admit new states and determine the boundaries of existing states. While the state legislature can propose changes or request adjustments to borders, any actual change must be approved by Congress.

This constitutional framework ensures that changes to state boundaries are carefully regulated and involve federal oversight. The other entities listed—such as the state legislature, governor, and supreme court—do not have the power to alter state boundaries independently without congressional approval. Thus, the correct answer reflects the proper understanding of the relationship between state and federal powers regarding boundary changes.