With the exception of carbon, hydrogen and oxygen________the most prevalent element in the living organisms

Options

A. Nitogen
B. Boron
C. Molybdenum
D. Copper

Explanation

To answer the question: "With the exception of carbon, hydrogen, and oxygen, ________ the most prevalent element in living organisms," we need to identify the most prevalent element after carbon, hydrogen, and oxygen.

### Step-by-Step Solution:

1. **Identify the Key Elements**: The question specifies that we should exclude carbon, hydrogen, and oxygen. These three elements are the most abundant in living organisms.

2. **Consider Other Elements**: After excluding the three mentioned elements, we need to think about other essential elements that are crucial for life. Common elements found in living organisms include nitrogen, phosphorus, sulfur, calcium, potassium, magnesium, and trace elements like iron, manganese, etc.

3. **Determine the Most Prevalent Element**: Among the elements listed, nitrogen is known to be the most prevalent after carbon, hydrogen, and oxygen. It is a major component of amino acids (the building blocks of proteins), nucleic acids (DNA and RNA), and is involved in various biological processes.

4. **Conclude the Answer**: Therefore, the answer to the question is nitrogen.

### Final Answer:
With the exception of carbon, hydrogen, and oxygen, **nitrogen** is the most prevalent element in living organisms.

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