Drama, Film, and Mass Communication homework help

Which one of the following is a balanced equation? A. Na (s) + MgF2 ? 2NaF (s) + Mg (s) B. 2Na (s) + MgF2 ? 2NaF (s) + Mg (s) C. Na (s) + O2 (g) ? Na2O D. Zn (s) + HCl (g) ? ZnCl2 (s) + H2 (g)