How do you find the bond enthalpy from an equation? Which equation represents the $\ce{N-H}$ bond enthalpy in $\ce{NH3}?$
$$
\begin{align}
&amp;\textbf{A.} &amp;\ce{NH3(g) &amp;-&gt; N(g) + 3 H(g)}\\
&amp;\textbf{B.} &amp;\ce{1/3 NH3(g) &amp;-&gt; 1/3 N2(g) + H(g)}\\
&amp;\textbf{C.} &amp;\ce{NH3(g) &amp;-&gt; 1/2 N2(g) + 3/2 H(g)}\\
&amp;\textbf{D.} &amp;\ce{NH3(g) &amp;-&gt; .NH2(g) + .H(g)}
\end{align}
$$

From what I've learnt, I understand that the bond enthalpy is defined as the energy required to break one mole of a specific bond.
In the question above, I opted for answer C as it was the only one with the products in the form of $\ce{N2}$ and $\ce{H2}.$ But since there are three $\ce{N-H}$ bonds in $\ce{NH3},$ I am unsure about answer B.
Can you clarify this?
Option D is the only one corresponding to the definition "energy required to break one mole of a specific bond" and nothing more.