Ahuman's most rapid growth, both physically and mentally, occurs between a0 and a1 years old.

Two and five

Explanation:

The most rapid growth of the human beings takes place at the age between 2 years and 5 years.

The physical and mental growth of the person also takes place at this age only. 90 per cent of the brain develops at this age and the person leans the ability to walk, talk, read, write, eat and everything that is required at that age and afterwards.

The person at this age has curiosity to learn about new things daily.

well wheres the question