Most of Mary's friends are other students that she spent time with on her freshman hall. They spent a lot of time together and remained great friends. What best explains this?

Answer: The effect of mere exposure explains this.

Explanation:

The effect of mere exposure is defined as a psychological phenomenon where repeated exposure to a stimulus can make a response to it more positive. That is, when a person is closer to something or someone, they may end up liking it. Some people listen to a song and say they don't like it, but once they continue to listen to it they tend to have a more positive opinion about it. Mary's case is similar.

Most of Mary's friends have spent a lot of time together for years, which means that their friendship remains strong. It is normal to see how a person, when away from someone, communication is lost and things are not the same again. As Mary's friends have remained together and in constant contact, they continue to maintain a similar relationship as they had at the beginning.