Under the Articles of Confederation, the national government had limited economic powers. Most notably, it did not have the power to impose taxes, regulate interstate commerce, or impose tariffs on imports effectively. The primary power it had related to economic matters was issuing currency. However, this power was also limited and often ineffective because the national government did not have the authority to enforce it robustly.
Therefore, the best response regarding the economic power of the national government under the Articles of Confederation is:
issuing currency.