The reactions indicate the formation of two compounds (A and C), which are position isomers. In these reactions, a Grignard reagent (CH₃MgBr) reacts with CH₃CHO, and the subsequent reaction with B₂H₆ leads to the formation of different products based on the position of functional groups (like -OH). Since the functional group (-OH) can be placed at different positions on the ring, this results in position isomers.
The correct answer is (B) : Position isomers.
The compounds \( [\text{PtCl}_2(\text{NH}_3)_4]\text{Br}_2 \) and \( [\text{PtBr}_2(\text{NH}_3)_4]\text{Cl}_2 \) constitute a pair of: