एरिक एरिक्सन के जीवन-अवधि विकास सिद्धांत के अनुसार, 'पहचान बनाम पहचान भ्रम' (Identity versus Identity Confusion) की अवस्था किस विकासात्मक अवधि की मुख्य विशेषता है?

According to Piaget, the stage in which children develop object permanence is:

Kohlberg's highest stage of moral development is characterized by:

Which of the following behaviors in early childhood would MOST strongly indicate a need for developmental screening for Intellectual and Developmental Disabilities (IDD)?