Erin realized that the arguing during a discussion was getting out of control, so she commented, "Before we all drive off a cliff, let's slow this car down and find some common ground." Her comment eased the tension in the room. Erin is demonstrating a role.

Maintenance role.

Explanation:

Roles are the part of individuals or groups' function in the society that should be played accordingly for smooth relationships within the society. Everyone has a role, maybe as parents, as students, as teachers or lecturers and so on.

In the question we can see that Erin was playing a type of role in that gathering or discussion group and that role is to help to foster peace and to ensure good interpersonal relationships. The act of doing this is known as the maintenance role.

the boundarys like convergent divergent and transform it causes subduction

i think it is the third one.