Industrial melanism is an evolutionary effect prominent in several arthropods.It caused black coating of moths for the adaptation in the present environment.
So option A is correct

Industrial melanism is a phenomenon where the frequency of dark-colored individuals in a population increases over time due to the effects of pollution. This is often observed in species of moths and insects that live in industrial areas with high levels of pollution. The increase in dark-colored individuals is a result of natural selection.

Natural selection:

Natural selection is the process by which certain traits or characteristics become more or less common in a population over time. This occurs because individuals with certain traits are better adapted to their environment and have a higher chance of surviving and reproducing, passing on their advantageous traits to the next generation.

In the case of industrial melanism, pollution causes changes in the environment, specifically in the coloration of the environment. Before industrialization, the environment was primarily light-colored, such as lichen-covered tree trunks. In this environment, light-colored individuals had a survival advantage as they were better camouflaged and less likely to be preyed upon.

However, with the advent of industrialization and the subsequent pollution, the environment became darker due to the accumulation of soot and other pollutants on surfaces. This change in the environment provided a new advantage to dark-colored individuals as they became better camouflaged against the darker background.

As a result, dark-colored individuals had a higher chance of survival and reproduction compared to light-colored individuals in the polluted environment. Over time, this led to an increase in the frequency of dark-colored individuals in the population, as they were more likely to pass on their genes for dark coloration to the next generation.

This increase in the frequency of dark-colored individuals is a prime example of natural selection. The change in the environment (pollution) created a new selective pressure that favored individuals with a specific trait (dark coloration). Through differential survival and reproduction, the population adapted to the new environmental conditions.

Other options:

Mutation refers to a change in the DNA sequence of an organism. While mutations can contribute to genetic variation, they do not specifically explain the increase in dark-colored individuals in industrial melanism.

Neo Lamarckism is a hypothesis that suggests acquired characteristics can be inherited. This contradicts the principles of modern genetics and natural selection, making it an unlikely explanation for industrial melanism.

Neo Darwinism is another term for the modern synthesis of evolutionary theory, which combines Darwinian natural selection with Mendelian genetics. It is a broader concept that encompasses natural selection as its central mechanism, making it a more accurate answer than Neo Lamarckism.

In conclusion, industrial melanism is an example of natural selection. The change in the environment due to pollution created a new selective pressure that favored dark-colored individuals, leading to an increase in their frequency in the population over time.