The role of government in enforcing antitrust laws

Understand the role of government in enforcing antitrust laws and its relevance to M&As: why is the enforcement of antitrust
laws important, and why may M&As become a concern? (Here, no need to know about individual laws and regulations; it will
suffice to be familiar with the importance of antitrust laws in general and the existence and role of regulators to enforce these
laws in the context of M&As).