Diamonds have sharp edges. Talc is softer than diamonds. Diamonds are very valuable. Talc and diamonds are both minerals.
I gave my students this multiple choice question: Students observed that a diamond was able to scratch a piece of talc. What does this observation best support?

Only one answer is correct among these 4 choices:
- Diamonds have sharp edges.
- Talc is softer than diamonds.
- Diamonds are very valuable.
- Talc and diamonds are both minerals.

Could you tell me which one is correct?

Talc is softer than diamonds.