With no explanation, chose the best option from "A" or "B". Kelsey has learned that her younger sister Deena has been bullying other kids at her school. Kelsey wants to teach Deena that being a bully is wrong.

A: Kelsey figures out what Deena has being doing to the other kids and starts doing the same to Deena at home.
B: Kelsey tells their parents what Deena has been doing.
B.