The EU's Antitrust Chief in November 2008 Fined Car Glass

The EU's antitrust chief in November 2008 fined car glass producers Asahi, Pilkington, Saint-Gobain and Soliver more than 1.3 billion euros ($1.66 billion) for price-fixing, the largest sum ever levied by the EU for a cartel. What are the economic justifications of making price fixing illegal?

A) Consumers suffer because of decreased consumer surplus and the outcome is inefficient because of deadweight loss.
B) An oligopoly cartel can maximize profit and behave like a natural monopoly.
C) The cartel increases quantity supplied in the market causing a shortage.
D) The cartel increases quantity supplied in the market causing a surplus and therefore harming other producers.