d
On dissolving alkali metal (sodium) in liquid ammonia, a deep blue solution is developed due to ammoniated electron which absorbs energy in visible region of light and imparts blue colour. Due to unpaired electron, solution is paramagnetic.

\(M +(x+y) NH _3 \rightarrow\left[ M \left( NH _3\right)\right]^{+}+\left[e\left( NH _3\right) y\right]^{-}\)

So, assertion statement is correct but reason is incorrect.