Which of the Following Concentrations Can Be Classified as a Conglomerate

Which of the following concentrations can be classified as a conglomerate concentration?

A) A concentration between undertakings which are competing in the same product and geographic market and at the same level of production/distribution.
B) A concentration between undertakings which are not competing with each other in any product market, and which does not result in any vertical integration.
C) A concentration between undertakings operating at different levels of the economy (e.g. between a manufacturer and its supplier of raw material)