Final answer:
Language skills must be mastered for optimal development at each life stage.
Step-by-step explanation:
For optimal development at each life stage, language skills must be mastered. Language is essential for communication and understanding, and it plays a crucial role in social interactions and relationships. Language skills enable individuals to express their thoughts, emotions, and needs effectively, which promotes healthy social development. For example, having strong communication skills allows individuals to engage in meaningful conversations, build friendships, and navigate various social situations.