Which of the following cannot be recycled? 

Cooker handles

The correct answer is option 2. Cooker handles.

The recyclability of items can vary depending on local recycling facilities and the materials used in the products. However, among the options provided, "Cooker handles" may be more challenging to recycle. This is because cooker handles are often made from mixed materials, such as a combination of plastic and metal, which can complicate the recycling process. Items made from multiple materials or those with complex designs may pose difficulties for recycling systems. Always check with local recycling guidelines to determine specific recyclability in your area.