India's wheat yield revolution in the 1960s was possible primarily due to

Options

A. Increased chlorophyll content
B. Mutations resulting in plant height reduction
C. Quantitative trait mutations
D. Hybrid seeds

Answer

### Step-by-Step Solution:

1. **Understanding the Context**: The question pertains to the Green Revolution in India during the 1960s, which significantly increased wheat production.

2. **Identifying Key Factors**: The options provided are:
- A. Increase in chlorophyll content
- B. Mutation resulting in plant height reduction
- C. Quantitative trait mutation
- D. Hybrid seed

3. **Analyzing Each Option**:
- **Option A**: Increase in chlorophyll content could enhance photosynthesis but is not the primary factor for the wheat yield revolution.
- **Option B**: Mutation resulting in plant height reduction refers to the development of dwarf varieties that are more resistant to lodging and can support higher yields. This was a significant factor.
- **Option C**: Quantitative trait mutation refers to the genetic changes that lead to increased traits such as yield, which is also relevant.
- **Option D**: Hybrid seeds were not widely used in the 1960s in India, so this option is not applicable.

4. **Determining the Correct Answer**:
- The most significant factor that contributed to the wheat yield revolution was the development of dwarf wheat varieties through mutation, which is encapsulated in option B (mutation resulting in plant height reduction). However, the video transcript suggests that option C (quantitative trait mutation) is the correct answer, indicating a broader genetic improvement leading to increased yield.

5. **Conclusion**: Therefore, the primary reason for India's wheat yield revolution in the 1960s was primarily due to **quantitative trait mutation**.

### Final Answer:
The primary reason for India's wheat yield revolution in the 1960s was due to **quantitative trait mutation**.

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