The complex $\left[\mathrm{Fe}(\text { phen })_{2}(\mathrm{NCS})_{2}\right]$ (phen 1,10-phenanthroline) shows spin cross-over behaviour CFSE and at $\mu_{\mathrm{eff}}$ 250 and 150 K, respectively are
(a)$0.4 Delta_{0}$, 4.90 BM and $2.4 Delta$,, 0.00 BM
(b)$2.4 \Delta_{0}$, 2.90 BM and $0.4 \Delta$, 1.77 BM
(c)$2.4 \Delta_{0}$, 0.00 BM and $0.4 \Delta$, 4.90 BM
(d)$1.2 \Delta_{0}$, 4.90 BM and $2.4 \Delta$. 0.00 BM