Given the fact "measuring the hardness of minerals requires scratching those materials", what is the answer to the question or completion "Hardness of minerals may be measured in certain ways, such as what?"

Choices: [-] heating the minerals to high temperatures. [-] applying pressure using a sharp, tough object in order to leave marks. [-] hitting the minerals with a tougher stone. [-] taking bits of metal and comparing the texture to the minerals.
applying pressure using a sharp, tough object in order to leave marks