Which of the four elements that make up 99% of all elements found in a living system are

Options

A. CHOS
B. CHOP
C. CHON
D. CNOP

Explanation

To answer the question regarding the four elements that make up 99% of all elements found in living systems, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Key Elements**:
- The question asks for the four elements that constitute the majority of elements in living organisms.

2. **List the Major Elements**:
- The four primary elements are:
- **Carbon (C)**: Essential for forming the backbone of organic molecules.
- **Hydrogen (H)**: A key component of water and organic compounds.
- **Oxygen (O)**: Vital for cellular respiration and a component of water and organic molecules.
- **Nitrogen (N)**: A crucial part of amino acids and nucleic acids.

3. **Confirm the Percentage**:
- Together, these four elements (C, H, O, and N) make up approximately 99% of the mass of living organisms.

4. **Consider Other Elements**:
- While there are other important elements like phosphorus (P) and sulfur (S), they do not constitute a significant percentage compared to the big four.

5. **Conclusion**:
- Therefore, the answer to the question is that the four elements making up 99% of all elements found in living systems are Carbon, Hydrogen, Oxygen, and Nitrogen.

### Final Answer:
The four elements that make up 99% of all elements found in living systems are **Carbon, Hydrogen, Oxygen, and Nitrogen**.

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