Examine the unbalanced chemical equation.

 NaCl +  F2 →  NaF +  Cl2

What coefficients should be placed in each blank in order to balance the equation?
A.
1, 2, 1, 2

B.
2, 1, 2, 1

C.
2, 2, 2, 2

D.
4, 2, 1, 2

B.

2, 1, 2, 1