Lawrence Kohlberg's cognitive developmental model of gender development posits that as children develop cognitive schemas, they engage in Gender Categorization (or category formation) to classify social roles, toys, and activities based on gender divisions.

• Basic Gender Identity (ages $2-3$) is simply labeling oneself and others as a boy or girl.
• Gender Stability (ages $3-4$) understands that gender remains the same over time.
• Gender Constancy (ages $6-7$) understands that gender does not change despite changes in hair or clothing.
• Gender Categorization represents the conceptual process where children construct mental social categories and organize environmental information around gender.

Key pillars and mandates of the National Education Policy (NEP 2020):
Statement (A) is correct: NEP strongly advocates instruction in the home language / mother tongue / regional language until at least Grade 5.
Statement (B) is correct: Ensures equitable and inclusive education for all socio-economically disadvantaged groups.
Statement (C) is correct: Emphasizes multidisciplinary, flexible, and holistic education across cognitive, emotional, and physical domains.
Statement (D) is incorrect: Rather than eliminating it, NEP integrates Early Childhood Care and Education (ECCE) into the formal schooling system starting at age 3.
Statement (E) is incorrect: NEP's pedagogical design is $5+3+3+4$, not $3+3+5+4$.

Jean Piaget demarcated cognitive development into four progressive chronological stages: 1. Sensorimotor stage (birth to $2\text{ years}$); 2. Preoperational stage ($2\text{ to } 7\text{ years}$); 3. Concrete operational stage ($7\text{ to } 11/12\text{ years}$), characterized by logical reasoning about concrete tangible events, reversibility, and mastery of conservation; 4. Formal operational stage ($12\text{ years and above}$), characterized by abstract and hypothetical thinking. Option analysis: (A) Sensorimotor is birth to 2 years. (B) Preoperational spans 2 to 7 years. (C) Concrete operational covers 7 to 12 years. (D) Formal operational is from 12 years into adulthood.