And I would add, for emphasis, that ALL of the subclauses must be satisfied, not just one (that is, you cannot pay attention to the part about foreign power while ignoring the part about subclause B) unless it said "OR" not "AND" following each caveat.
Read the law carefully and you will see that's not the case.
The argument you are making would apply to a foreign group with members that claim that they are American persons based on arguments OTHER than those found in subsection B (i.e. American citizenship, and I believe legal residence) perhaps by making claims of ties to American relatives, or working for an American company.