ICBN was first revised in :-

Options

A. 1961
B. 1964
C. 1975
D. 1753

Answer

To answer the question "ICBN was first revised in:", we can break down the solution into several steps:

### Step-by-Step Solution:

1. **Understanding ICBN**:
- ICBN stands for the International Code of Botanical Nomenclature. It is a set of rules and recommendations for naming plants scientifically.

2. **Historical Context**:
- The ICBN was originally proposed by Sprague, Hitchcock, and Green in the year 1930. This establishes the timeline for when the code was first introduced.

3. **First Revision**:
- The first revision of the ICBN took place during the 12th International Congress of Botany, which was held in Leningrad in 1975. This is a crucial point as it marks the first formal revision of the code.

4. **Publication of Revised Code**:
- After the revision in 1975, the revised ICBN was published in 1978. However, the question specifically asks for the year of the first revision, not the publication.

5. **Conclusion**:
- Based on the information gathered, the first revision of the ICBN occurred in 1975. Therefore, the correct answer is 1975.

### Final Answer:
The ICBN was first revised in **1975**.

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