Here's a problem to solve: A student is trying to identify a mineral that has a nonmetallic luster and is black. It can also be scratched with a fingernail. According to the mineral reference sheet, the unidentified mineral is most likely

Among the 4 following options, which is the correct answer?

- A: mica.
 
- B: magnetite.
 
- C: hornblende.
 
- D: quartz.
 