Answer:C
Explanation:
Mountains can change in several ways over time. They can undergo erosion by rain and wind, as well as landslides due to flooding. Some mountains change via volcanic activity.
<span>Experimenter bias, this is related to the threats to internal validity. This means, that in a scientific research where you want to get a very specific result, there could be variations and an unconscious influence on the experimental group's opinion or mindset. there are many ways this could happen, and to prevent experimenter bias there are several strategies to follow.</span>
<span>Actually an oligarchy is a form of government where a
certain group of people are in power. It
is usually controlled by rich and powerful families who establish political
dynasties to ensure the continuation of power. It can also be a military junta who came into
power under certain circumstances. Usually they rely on oppression to rule over
people.</span>