Answer:
![\boxed {\boxed {\sf B. \ 9 \ states}}](https://img.qammunity.org/2021/formulas/social-studies/high-school/2bcidl2k16keqsfy2fcqbwf8uuojzmakei.png)
Step-by-step explanation:
The Articles of Confederation was America's first constitution or plan for the government. The founders made the government intentionally weak, because they were afraid of another tyrannical king. Unfortunately, the weakness and decentralization led to their ultimate failure. One reason for their downfall was how many states had to agree for changes to be made.
If a law was to pass, 9 of 13 states had to agree. An amendment or change to the Articles themselves required all thirteen states to agree.
Since this question asks about a law, the correct answer is 9 states.