The standard enthalpy of formation of $NH_3$ is $-46\: kJ/mol.$ If the enthalpy of formation of $H_2$ from its atoms is $-436\: kJ/mol$ and that of $N_2$ is $-712\: kJ/mol$, the average bond enthalpy of $N-H$ bond in $NH_3$ is

Question

$\begin {array} {1 1} (A)\;-964\: kJ/mol & \quad (B)\;352\: kJ/mol \\ (C)\; 1056\: kJ/mol & \quad (D)\;-1102 \: kJ/mol \end {array}$