Arrange the words in a meaningful logical order and select the appropriate sequence :

1. Toddlerhood

2. Adulthood

3. Infancy

4. Childhood

5. Old age

Given: 

1. Toddlerhood 2. Adulthood 3. Infancy 4. Childhood 5. Old age

Now, arrange them in proper life order:

Infancy (3) – newborn stage, 0 – 1 years

Toddlerhood (1) – walking age, 1 – 3 years

Childhood (4) – school age, 4 – 12 years

Adulthood (2) – working, mature age

Old age (5) – senior stage, after retirement

So the correct sequence is: 31425

Thus, correct option is (d).