Sodium metal reacts (very vigorously!) with bromine liquid according to the balanced equation:
2 Na(s) + Br2(l) → 2 NaBr(s) + heat

If x is the number of moles of NaBr that are produced, then the number of moles of Br2 required would have been:
A) x/2
B) x
C) 2x
D) 4x
E) x²