The correct answer is: Only I and IV are strong.
Argument I is strong because it is based on the idea that competition is good for children. It suggests that children who are motivated to study will learn more and be more successful in life.
Argument IV is strong because it is based on the idea that children need to have time to play. It suggests that too much pressure on children can lead to stress and anxiety.
Argument II is weak because it is based on the idea that children will not enjoy studying if they are forced to do it. This is not necessarily true, as some children enjoy learning even when they are not forced to do so.
Argument III is weak because it is based on the idea that children need to be prepared for difficult examinations from a young age. This is not necessarily true, as children can learn how to cope with difficult examinations at a later age.
In conclusion, only arguments I and IV are strong.