Which of the Following Statements Best Describes the Concentration Movement

Which of the following statements best describes the concentration movement between 1875-1905?

A) There were two phases, the first of which had relatively more horizontal mergers and the second had relatively more vertical mergers.
B) The first phase focused on vertical mergers, the second was a period of relative inactivity in acquisitions, and the third decade was one of horizontal mergers.
C) There were three phases, the first of which had relatively more vertical mergers and the second had relatively more horizontal mergers.
D) There were two waves of mergers. In the first wave most mergers were motivated by the desire to obtain monopoly profits and the second wave was obtained through greater economies of scale.