Most abundant elements in the living cells are

Options

A. C, O, N and P
B. C, H, O and Ca
C. C, H, O and N
D. C, H, Mg and N

Answer

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks for the most abundant elements in living cells.

2. **Consider the Options**: The options provided are:
- A) Carbon, Oxygen, Nitrogen, and Phosphorus
- B) Carbon, Hydrogen, Oxygen, and Calcium
- C) Carbon, Hydrogen, Oxygen, and Nitrogen
- D) Carbon, Hydrogen, Magnesium, and Nitrogen

3. **Analyze Each Option**:
- **Option A**: Carbon, Oxygen, Nitrogen, and Phosphorus. While phosphorus is important, it is not one of the most abundant elements in living cells.
- **Option B**: Carbon, Hydrogen, Oxygen, and Calcium. Calcium is essential for certain functions but is not as abundant as the other elements listed.
- **Option C**: Carbon, Hydrogen, Oxygen, and Nitrogen. These four elements are fundamental to the structure of carbohydrates, proteins, and nucleic acids, making them the most abundant in living cells.
- **Option D**: Carbon, Hydrogen, Magnesium, and Nitrogen. Magnesium is important but is not one of the most abundant elements in living cells.

4. **Conclusion**: After analyzing the options, the most abundant elements in living cells are indeed Carbon, Hydrogen, Oxygen, and Nitrogen.

5. **Final Answer**: The correct answer is **C) Carbon, Hydrogen, Oxygen, and Nitrogen**.

---