Specify whether the following pairs of structures depict constitutional isomers, stereoisomers, conformers, or different compounds.

• A. (i) Stereoisomers
  (ii) Conformers
• B. (i) Different compounds
  (ii) Conformers
• C. (i) Different compounds
  (ii) Constitutional isomers
• D. (i) Stereoisomers
  (ii) Constitutional isomers

Answer: (A)