1.
Among (i) [Cr(en)3_3]3+^{3+}, (ii) trans-[Cr(en)2_2Cl2_2]+^+, (iii) cis-[Cr(en)2_2Cl2_2]+^+, (iv) [Co(NH3_3)4_4Cl2_2]+^+ the optically active complexes are