At Present, One Flaw with the Agreement on Internal Trade

At present, one flaw with the Agreement on Internal Trade is that

A) trade between Canada's provinces remains limited and there are few opportunities to challenge existing provincial practices.
B) its dispute settlement mechanism can only be invoked by governments.
C) decisions under its dispute settlement mechanism are not legally binding.
D) it has not been adhered to by all the provinces.
E) coverage is limited to a few areas, but many more must be negotiated.