How are the ingredients in a mixture of iron filings and sand affected by being combined?
answer choices

1. Both the iron filings and the sand maintain their original physical properties when combined.

2. The physical properties of the sand change but those of the iron filings do not.

3. Neither the iron filings nor the sand maintain their original physical properties when combined.

4. The physical properties of the iron filings change but those of the sand do not.