The correct answer is option 1 - lead. When food is wrapped in newspaper, especially if it is warm or oily, there is a risk of contamination with lead.

Newspaper ink contains lead which can easily transfer to the food it comes in contact with. Lead is a toxic metal and ingesting it can have serious health effects, especially for children and pregnant women.

Options 2, 3, and 4 (aluminium, iron, and magnesium) are not likely to contaminate food when wrapped in newspaper. Aluminium is commonly used in food packaging and is considered safe. Iron and magnesium are essential minerals that are naturally present in our diet and do not pose a contamination risk when used with newspaper.

It is important to note that using newspaper as a food wrapper is not recommended due to the potential for contamination. It is better to use food-grade wrapping materials that are specifically designed for food contact to ensure the safety of the food we consume.