Life originated in which duration:

Options

A. Proterozoic
B. Mesozoic
C. Precambrian
D. Cenozoic

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the duration in which life originated on Earth.

2. **Analyzing the Options**:
- **Option 1: Proterozoic**: This is a geological eon that follows the Archean eon and precedes the Phanerozoic eon. It is characterized by the appearance of oxygen in the atmosphere, but it is not the time when life first originated. Therefore, this option is incorrect.

- **Option 2: Mesozoic**: This era is known as the Age of Reptiles and spans from about 252 to 66 million years ago. It is well-known for the dominance of dinosaurs and is not the period when life first appeared. Hence, this option is also incorrect.

- **Option 3: Cenozoic**: This is the current geological era, often referred to as the Age of Mammals. It began around 66 million years ago and is not the time of life's origin. Thus, this option is incorrect as well.

3. **Identifying the Correct Answer**: The question implies that life originated in the Precambrian eon, which is the largest span of geological time before the Phanerozoic eon. This eon includes both the Archean and Proterozoic eons, and it is believed that all life forms originated during this time.

4. **Conclusion**: The correct answer to the question is that life originated in the **Precambrian eon**.

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