Final answer:
The first approach is the command-and-control policy as it involves direct government mandates on specific technologies to use for reducing emissions.
Step-by-step explanation:
When considering approaches to reducing emissions of CO₂ from manufacturing industries, the first approach, where the U.S. government makes it a policy to use only predetermined technologies, is an example of a command-and-control policy. This is because command-and-control regulation involves government mandates on what technologies must be used or how much pollution can be emitted. The second approach, which involves determining which technologies are cleaner and subsidizing their use, is more aligned with market incentives, since it encourages firms to choose the cleaner technology through financial support rather than direct regulation.