What process is most responsible for the extinction of most species of plants and animals that have lived on Earth? A. gene mutation B. environmental changes C. selective breeding D. decrease in reproduction

The process most responsible for the extinction of most species of plants and animals that have lived on Earth is B. environmental changes.

Here's a step-by-step explanation:

1. Gene mutation: While gene mutation can lead to the extinction of a species, it is not the most common cause. Mutations can sometimes be beneficial and lead to evolution rather than extinction.

2. Environmental changes: This is the most common cause of extinction. Changes in the environment, such as climate change, habitat destruction, or the introduction of new predators or diseases, can lead to the extinction of species that are unable to adapt to these changes.

3. Selective breeding: This is a process controlled by humans and is not a natural cause of extinction. While it can lead to the loss of genetic diversity, it does not typically result in extinction.

4. Decrease in reproduction: A decrease in reproduction can lead to extinction, but it is usually a symptom of other problems (like environmental changes or disease) rather than a cause in itself.