Which one of the following structures is indicative of meridonial isomer ?

Meridional isomer is also known as mer isomer, while facial isomer is also known as fac isomer. Geometric isomers include facial and meridian isomers. An octahedral complex Ma₃bcd or Ma₃b₂c type in which three ligands must be identical contains these isomers. If the three ligands of one type form a trigonal plane then the isomer is fac and if the three ligands of the same type do not form a trigonal plane then the isomer is mer (meridional).