a
\(\left[ Cr \left( H _{2} O \right)_{4} Cl _{2}\right]^{+}\) shows geometrical isomerism because it is a \(MA _{4} B _{2}\) type coordination compound which contains two set of equivalent ligands, four \(H_{2} O\) and \(2 C l\). Hence, the possible geometrical isomers are:
Hence, correct option is \(( A )\)
