Determine structures that correspond to the same compound. Also identify structures that correspond to different compounds.

• A. Structures 1 and 2: 2,3-dimethylpentane;
  Structures 3, 4 and 5: 2,2-dimethylpentane
• B. Structures 1, 2 and 3: 2,3-dimethylpentane;
  Structures 4 and 5: 2,2-dimethylpentane
• C. Structures 1, 2 and 4: 2,3-dimethylpentane;
  Structures 3 and 5: 2,2-dimethylpentane
• D. Structures 1, 2 and 5: 2,3-dimethylpentane;
  Structures 3 and 4: 2,2-dimethylpentane

Answer: (C)