Which of the following was a weakness of the articles of confederation?

A. congress could not regulate frontier settlement
B. congress could not establish a common currency
C. congress could not negotiate with foreign powers
D. congress could not make laws

B. Congress could not establish a common currency

Congress did have the power to create laws. However, there was no executive branch to enforce these laws.

Back then there was no national currency. Each state had there own form of currency, which would become a problem.