Explanation:

- Article 24 of the Constitution of India explicitly prohibits the employment of children below a certain age in factories and other hazardous employment.

- According to Article 24, a child below the age of 14 years cannot be employed in any factory.

- This restriction is part of the efforts to protect children from engaging in labor that could harm their health or development.

- Option 1, age 16, is incorrect as Article 24 specifies under 14, not 16.

- Option 3, age 15, is also incorrect for the same reason.

- Option 4, age 17, is not relevant as no explicit mention is made in Article 24 about age 17.