Lawrence Kohlberg argued that :

Correct Option: moral development occurs progressively in stages.

Step-by-Step Explanation:

1. Understanding Lawrence Kohlberg's Theory:
Lawrence Kohlberg was an American psychologist best known for his theory of stages of moral development. He adapted and expanded upon Jean Piaget's cognitive development work to explain how children develop moral reasoning.

2. The Stage-Based Approach:
Kohlberg proposed that moral development occurs progressively through a fixed sequence of three main levels, each divided into two stages (making six stages in total):
• Pre-Conventional Level: Moral reasoning is based on external rewards and punishments (Obedience and Punishment, Self-Interest).
• Conventional Level: Moral reasoning is governed by social approval, social order, and rules (Interpersonal Accord/Conformity, Authority and Social Order).
• Post-Conventional Level: Moral reasoning is based on abstract principles of justice, individual rights, and universal ethical values (Social Contract, Universal Ethical Principles).

3. Evaluating the Options:
• Continuous manner: Kohlberg viewed moral development as qualitative shifts between distinct stages, rather than a continuous linear accretion.
• Cultural differences / Gender differences: While later critics (such as Carol Gilligan regarding gender bias) highlighted these aspects, Kohlberg's core original thesis posited that moral reasoning develops in universal, progressive cognitive stages.
• Progressive stages: This is the fundamental hallmark of Kohlberg's theory—that individuals progress through defined stages of moral reasoning sequentially as their cognitive capabilities expand.

Therefore, the core statement argued by Lawrence Kohlberg is that moral development occurs progressively in stages.