Read the following paragraph and answer the question. Give ONLY the answer, no other words or explanation.

For example:

Answer: <most likely answer, as short as possible>.

Paragraph: 
Magnetism is the ability of a material to be attracted by a magnet and to act as a magnet. No doubt you’ve handled refrigerator magnets like the ones in Figure below . You probably know first-hand that they stick to a metal refrigerator but not to surfaces such as wooden doors and glass windows. Wood and glass aren’t attracted to a magnet, whereas the steel refrigerator is. Obviously, only certain materials respond to magnetic force.


Question: Unlike wood and glass, steel is an example of a material that responds to what force?
magnetic
Magnetic force.