The correct answer is conventional
One of the influential theories of moral development was put forward by Lawrence Kohlberg, an American psychologist who lived between 1927 and 1987, and related moral development to the child's cognitive development.
He pointed out that through a maturational and interactive process, everyone has the ability to reach full moral competence. In his main study, he interviewed 72 10-, 13-, and 16-year-old from around Chicago. He presented them with a series of moral dilemmas, which explained how they came up with solutions, and even accompanied some of the subjects for about 20 years.