Final answer:
When compressing Earth's history into an hour, humans would appear in the final few seconds, specifically less than 1 second ago, making the correct answer B. 1 second ago.
Step-by-step explanation:
If we consider all of Earth's history compressed into an hour, humans first appear on this timeline extremely recently.
Humans have inhabited this planet for only the last 2.5 million years, and anatomically modern humans have been around for about 200,000 years.
When scaled down to an hourly timeframe, humans would have appeared in the last few seconds, making the correct answer B. 1 second ago.
The Earth was formed 4.54 billion years ago, and life started with simple microorganisms. Spending billions of years evolving, complex life forms emerged and diversified.
It's only in the last fraction of Earth's timeline that humans emerged and made a significant impact on the planet's history and its biosphere.