The Lawsuit the Justice Department Brought Against Apple Regarding the Pricing

The lawsuit the Justice Department brought against Apple regarding the pricing of e-books for its iPad is an example of attempts by the government

A) to prevent vertical mergers which would significantly reduce competition.
B) to prevent horizontal mergers which would significantly reduce competition.
C) to regulate a natural monopoly by establishing government-regulated prices.
D) to keep firms from artificially restricting competition to raise prices.