Please explain this with solutionthat is simple

Dear Student,
As per Curie law, for a paramagnetic substance
$$\begin{gathered} \chi \propto \frac{1}{T} \\ \chi =\frac{C}{T}, where C is the Curie cons\tan t \\ given, \\ When \chi =0.5, \frac{1}{T}=5\times {10}^3 /K \\ So, \\ C=\chi T=0.5\times \frac{1}{5\times {10}^3}=100 K \\ Ans \left(c\right) \\ Regards \end{gathered}$$: