Identify correct statements about flow diagrams:
(A) When part of the commodity is diverted to a different direction, the main flowline also becomes thicker proportionately.
(B) The thickness of the lines is determined by the volume or quantity of flow.
(C) Movement of goods can be shown only in one direction.
(D) These are not suitable to represent international, national or regional flow of various commodities.
Choose the correct answer from the options given below: