Life has existed on earth for the last

Options

A. 2-3 billion years
B. 3-5 billion years
C. 4-3 billion years
D. 5-0 billion years

Answer

To answer the question "Life has existed on earth for the last," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Age of Earth**:
- The Earth is approximately 4.5 billion years old. This is a crucial piece of information as it sets the context for the existence of life.

2. **Identifying the Origin of Life**:
- Life on Earth is believed to have first appeared around 3.5 to 4.0 billion years ago. The earliest known life forms are microfossils of bacteria.

3. **Determining the Duration of Life on Earth**:
- If life began around 3.5 to 4.0 billion years ago, we can calculate the duration of life on Earth by subtracting this time from the current age of the Earth.

4. **Calculating the Time Frame**:
- Given that the current age of the Earth is about 4.5 billion years, and life began approximately 3.5 to 4.0 billion years ago, we can conclude that life has existed on Earth for about 3 to 5 billion years.

5. **Choosing the Correct Option**:
- The options provided are:
- 2 to 3 billion years
- 3 to 5 billion years
- 4 to 3 billion years
- 5 to 0 billion years
- Based on our calculations, the correct option is **3 to 5 billion years**.

### Final Answer:
Life has existed on Earth for the last **3 to 5 billion years**.

---