Finish the following sentence with the best choice: To make homemade magnetic silly putty,

Choices:
- take regular silly putty, form it into a bowl shape, put some aluminum oxide and knead till it is mixed and the texture is grainy.
- take regular silly putty, form it into a bowl shape, put some iron oxide and knead till it is mixed and the texture is grainy.

Answer:
take regular silly putty, form it into a bowl shape, put some iron oxide and knead till it is mixed and the texture is grainy.