In a Multilevel Model in Which an Outcome Was Measured

In a multilevel model in which an outcome was measured in children from different classrooms, a large intraclass correlation would imply that:

A) The outcome measure varied a lot across children within a classroom.
B) Children within a particular class behaved very differently.
C) Children in different classes behaved very differently.
D) The outcome variable varied very little across children from different classrooms.