Answer:
The correct answer is: B. 2,000.
Step-by-step explanation:
Humans have become the dominant species on Earth in the last approximately 2,000 years. This period corresponds to the rise and spread of human civilizations, advancements in technology, and significant changes in human population and impact on the environment. While human ancestors have existed for millions of years, it is within the last 2,000 years that humans have exerted a significant and widespread influence on the planet.