Meanings of these words are as follows – Infancy: The state or period of babyhood or early childhood. Childhood: The state or period of being a child. Adolescence: The period following which a young person develops from a child into an adult. Adulthood: The state or condition of being fully grown or mature. Senility: The condition or process of deterioration with age. Hence, the correct order is Infancy, Childhood, Adolescence, Adulthood, and Senility. Thus,5, 1, 3, 2, 4 is the correct order