human
Question: Hardness of minerals may be measured in certain ways, such as what?

Choices:
A) heating the minerals to high temperatures
B) applying pressure using a sharp, tough object in order to leave marks
C) hitting the minerals with a tougher stone
D) taking bits of metal and comparing the texture to the minerals
gpt
The correct answer is 1: applying pressure using a sharp, tough object in order to leave marks.