A reaction of cobalt(III) chloride and ethylenediamine in a 1 : 2 mole ratio generates two isomeric products A (violet coloured) and B (green coloured). A can show optical activity, but, B is optically inactive. What type of isomers does A and B represent?
(1) Coordination isomers
(2) Linkage isomers
(3) Geometrical isomers
(4) Ionisation isomers
