The most abundant chemical in living organisms could be

Options

A. protein
B. water
C. sugar
D. nucleic acid

Explanation

To determine the most abundant chemical in living organisms, let's analyze the options provided: protein, water, sugar, and nucleic acid.

**Step 1: Identify the options**
- The options given are:
1. Protein
2. Water
3. Sugar
4. Nucleic acid

**Step 2: Analyze each option**
- **Protein**: While proteins are essential for various functions in living organisms, they are not the most abundant chemical.
- **Water**: Water is a vital component of all living cells and constitutes a significant portion of the mass of organisms. It is known to be the most abundant chemical in living organisms.
- **Sugar**: Sugars are important for energy and structural functions, but they are present in smaller quantities compared to water.
- **Nucleic acid**: Nucleic acids (DNA and RNA) are crucial for genetic information, but they are also less abundant than water.

**Step 3: Conclusion**
Based on the analysis, the most abundant chemical in living organisms is **water**. It plays a critical role in metabolic processes and is essential for life.

**Final Answer: Water (Option B)**

---