Which quotation below best supports the idea that the common good becomes more important to people as the age?

Once a person begins to think in a Stage 5 way about what benefits the community as a whole, they will almost never go back to a Stage 2 level of looking out for themselves first.

Explanation:

The options you were given are the following:

Kohlberg came up with a theory to describe the different ways that human beings make moral choices.
They tend to follow the rules that their parents and teachers make because they are thinking about getting something good or not getting in trouble.
They see rules as being the same for everyone, and they think it is important and valuable to do what one is ‘supposed’ to do.
Once a person begins to think in a Stage 5 way about what benefits the community as a whole, they will almost never go back to a Stage 2 level of looking out for themselves first.

The given question refers to a text about the stages of moral development defined by American psychologist Lawrence Kohlberg. According to him, there are six stages of moral development, and the more we grow and progress as individuals, the higher the stage we're on is.

The quote that best supports the idea that the common good becomes more important to people as we age is the fourth one: Once a person begins to think in a Stage 5 way about what benefits the community as a whole, they will almost never go back to a Stage 2 level of looking out for themselves first.

Stage 2 is usually present in children when they still aren't familiar with the concept of the common good. A child can't be at Stage 5, and an adult who has reached it will never go back to Stage 2. A person who cares about their community and other people will not regress.

This is why the fourth option is the correct one.