Water is the second most important factor influencing life of organisms because

Options

A. it makes major part of an organism's body
B. productivity of plants depend upon availability of water
C. life on Earth originated in water
D. both (a) and (b)

Explanation

**Step-by-Step Solution:**

1. **Understanding the Importance of Water:**
- Water is essential for all living organisms. It plays a crucial role in various biological processes, making it one of the most important factors influencing life.

2. **Analyzing the Options:**
- Option A: "It makes a major part of the organism's body."
- This is true. Water constitutes a significant portion of the body mass of most organisms, often around 70-90% in animals and even higher in plants.
- Option B: "Productivity of plants depends upon the availability of water."
- This is also true. Water is vital for photosynthesis, nutrient transport, and overall plant health, directly affecting plant productivity.

3. **Considering Other Factors:**
- While temperature is another critical factor influencing life, the question specifically asks about the importance of water as the second most important factor.

4. **Conclusion:**
- Since both statements in options A and B are correct, the combined answer is that water is crucial for both the composition of organisms and the productivity of plants.

5. **Final Answer:**
- Therefore, the correct answer is option 4: "Both A and B."

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