Among these Options the Option B contains a Balance chemical equation. Equation is as follow,
2Na ₍s₎ + MgF₂ → 2NaF ₍s₎ + Mg ₍s₎
There are two Na atoms (or moles) at right hand side and two at left hand side.
There are two F atoms (or moles) at right hand side and two at left hand side.
There is one Mg atom (or mole) at right hand side and one at left hand side.