Could you give an advice?

A Family Problem

Mr. and Mrs. Hill don't know what to do about their 15-year-old son, Mark. He's very intelligent but has no interest in learning. His grades are getting worse, and he won't do any homework. Sometimes he skips school and spends the day at the mall.

His older sister Kathy is a good student, and she never causes any problems at home. Kathy hasn't missed a day of school all year. Mark's parents keep asking him why he can't be more like Kathy. Mark is jealous of Kathy and picks fights with her.

All Mark likes to do is stay in his bedroom and listen to loud music or play video games. He often refuses to eat meals with his family. He argues with his parents, his room is a mess, and he won't help around the house.