Why Would a Competition Regulator Need Details Relating to How

Why would a competition regulator need details relating to how firms are competing to cut prices, raise output levels, or build a high quality reputation?

A) to be able to determine and specify how competition occurs in an industry
B) to build a statistical model to estimate the likely outcome of a merger
C) to block mergers that would reduce competition and harm consumers
D) to permit competitive mergers to proceed, as well as all of the above