Answer:
B) Mixed economy
Step-by-step explanation:
Pure capitalism would involve no government interference in the economy. However, this pure form of capitalism no longer exists in the US. This pure form of capitalism caused significant problems in the late 1800's and early 1900's. This includes fights between workers and management, labor strikes, poor/unsafe working conditions, etc.
This is why the US uses a mixed economy. The government makes law for businesses to follow to ensure safe working conditions, allow for competition between businesses, etc.