Denise and her friends have formed an in-group. what does this mean
a. they feel comfortable with and loyal to each other
b. they are all the same age
c. they follow the examples set by other groups
d. they live in a large community

a. They feel comfortable with and loyal to each other.

Explanation:

In sociology and social psychology, an in-group is a social gathering of people to which each individual declares membership. That membership usually relates to their race, culture, gender, age, or religion, depending on what each person finds meaningful in their view of themselves. In-groups are an essential fount of belonging and self-esteem because they provide a sense of social identity.

c. taught scientists many new things about the earth, but not other planets.

explanation: