Read the following statements and select the correct option.
(i) Increase in metained months after industrialisation in Great Britain is a proof for natural selection.
(ii) When more individuals of a population acquire a mean character value, it is called disruption.
(iii) Changes in allelic frequency in a population will lead to Hardy-Weinberg equilibrium.
(iv) Genetic drift changes the existing gene or allelic frequency in future generations.

Options

A. Only ii is correct.
B. Only iv is correct.
C. Both I and iv are correct.
D. Both I and ii are correct.

Explanation

To solve the question, we need to evaluate each of the four statements provided and determine which are correct.

### Step-by-Step Solution:

1. **Evaluate Statement (i)**:
- **Statement**: "Increase in melanized moths after industrialization in Great Britain is a proof for natural selection."
- **Analysis**: This statement is correct. The increase in the number of melanized (dark-colored) moths after industrialization is a classic example of natural selection. The darker moths had a survival advantage in soot-covered environments, leading to their increased frequency in the population.

2. **Evaluate Statement (ii)**:
- **Statement**: "When more individuals of a population acquire a mean character value, it is called disruption."
- **Analysis**: This statement is incorrect. The correct term for when more individuals acquire a mean character value is "stabilizing selection," not "disruption." Disruptive selection refers to a situation where extreme values for a trait are favored over intermediate values.

3. **Evaluate Statement (iii)**:
- **Statement**: "Changes in allelic frequency in a population will lead to Hardy-Weinberg equilibrium."
- **Analysis**: This statement is also incorrect. The Hardy-Weinberg equilibrium is maintained when allele frequencies remain stable. Changes in allelic frequency would disrupt the equilibrium, not lead to it.

4. **Evaluate Statement (iv)**:
- **Statement**: "Genetic drift changes the existing gene or allelic frequency in future generations."
- **Analysis**: This statement is correct. Genetic drift refers to random changes in allele frequencies in a population, which can lead to significant changes over generations, especially in small populations.

### Conclusion:
Based on the evaluations:
- Statement (i) is correct.
- Statement (ii) is incorrect.
- Statement (iii) is incorrect.
- Statement (iv) is correct.

Thus, the correct statements are (i) and (iv), leading us to select option C.

### Final Answer:
The correct option is C (i and iv are correct).