The separation of two chromatids of each chromosome at early anaphase is initiated by

Options

A. (a) the interaction of centromere with the chromosomal fibres
B. (b) the elongation of metaphasic spindle
C. (c) the force of repulsion between the divided kinetochores
D. (d) all of these

Explanation

### Step-by-Step Solution:

1. **Understanding Anaphase**:
- Anaphase is a stage of mitosis that occurs after metaphase. During this phase, the replicated chromosomes are separated into two daughter chromatids.

2. **Mechanism of Chromatid Separation**:
- The separation of the chromatids occurs as they are pulled apart towards opposite poles of the cell. This movement is facilitated by the contraction of spindle fibers.

3. **Role of Spindle Fibers**:
- Spindle fibers originate from the centrioles and attach to the chromosomes at the centromere. The contraction of these spindle fibers is crucial for the movement of chromatids.

4. **Kinetochore Function**:
- The kinetochores are protein complexes that form at the centromere during cell division. They play a significant role in the separation of chromatids.

5. **Force of Repulsion**:
- The initiation of the separation of chromatids at early anaphase is primarily due to the force of repulsion generated between the divided kinetochores. As the kinetochores move apart, they exert a repulsive force on each other, which aids in the separation of the chromatids.

6. **Conclusion**:
- Therefore, the correct answer to the question regarding what initiates the separation of chromatids at early anaphase is option C: the force of repulsion between the divided kinetochores.

### Final Statement:
Hence, the correct answer is option C, the force of repulsion between the divided kinetochores.

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