Why Were the European Emissions Trading Scheme Credits Given to Existing

Why were the European Emissions Trading Scheme credits given to existing companies,rather than auctioned off?

A) It was more efficient to give away the credits than to stage an auction.
B) The Europeans found out that firms could not afford to purchase the credits and pay for the technology to reduce emissions.
C) Consumers successfully lobbied to have the credits given out for free so that firms would not have to raise the prices of their products.
D) Firms successfully lobbied to have the credits given out for free so that they would not have to pay for them.