Which example clearly shows the difference between hazardous child labour and ordinary help?

Correct answer: A thirteen year old works in a firecracker factory

The direct answer is A: a thirteen-year-old working in a firecracker factory clearly shows hazardous child labour. Children need protection from work that can cause injury, illness, or harm their development, especially in dangerous industrial settings. The reasoning is: the person is below the protected age; the workplace contains serious physical risks such as fire, explosions, or harmful substances; therefore this is not ordinary help but hazardous child labour. Option A is correct. Option B, arranging books at home, is ordinary family help as described and does not show a dangerous workplace. Option C, taking part in sport, is recreation, not employment. Option D, doing school drawing, is education and creative activity, not labour exploitation. The question asks for the example that makes the difference clearest, so the factory setting and young age are decisive clues. Remember: young child plus dangerous workplace requires immediate concern.