Noah Webster's quote reflects his concern about the power of individual states to undermine the collective decisions of the confederation. The fundamental problem he saw in the Articles of Confederation was:
D) that states would always work in their own self-interest even if it meant harm to the nation as a whole.
Webster believed that the lack of a strong central authority would lead to a fragmented union where individual states could act contrary to the interests of the collective, thus rendering the confederation ineffective.