From the following reactions,predict which of the following orders regarding acid strength is correct? $$\begin{array}{1 1}HC\equiv CH+LiNH_2\quad\leftrightharpoons\quad NH_3+HC\equiv CLi\\NH_3+R^-\quad\leftrightharpoons \quad NH_2^-+RH\end{array}$$

Question

$\begin{array}{1 1}(a)\;RH < NH_3 < HC \equiv CH\\(b)\;RH > NH_3 > HC \equiv CH\\(c)\;RH > NH_3 < HC \equiv CH\\(d)\;RH < NH_3 > HC \equiv CH\end{array}$