c
\(\begin{gathered}
\tau \,\, = \,\,\,I\,\,\alpha \,\,\therefore \,\,{10^5}\,\, = \,\,m{K^2}\,\alpha \,\, \hfill \\
\therefore \,\,\alpha \,\, = \,\,\frac{{{{10}^5}}}{{m{K^2}}}\,\,\therefore \,\,\alpha \,\, = \,\,\frac{{{{10}^5}}}{{10\,\, \times \,\,2500}}\, \hfill \\
\end{gathered} \)
\(\therefore \,\,\alpha \,\, = \,\,4\,\,rad\,\,/\,\,{s^2}\)