Here's a problem to solve: The chemical symbol for niobium is Nb. Based on its symbol, what can be concluded about niobium?

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

- A: Niobium is a compound.
 
- B: Niobium is an element.
 
- C: Niobium is a metal.
 
- D: Niobium is a mixture.
 