$Na$ and $Li$ are burnt in dry air we get

Question

$\begin{array}{1 1}(1)\;NaOH,Na_2O,Li_2O\\(2)\;Na_2O,Li_2O\\(3)\;Na_2O,Li_3N,Li_2O,NH_3\\(4)\;Na_2O,Li_3N,Li_2O\end{array}$

$(a)\;1,2\qquad(b)\;1,2,3\qquad(c)\;2,3\qquad(d)\;4$