Write the appropriate structural formule for:
a. A cyclic molecule that is a consitutional isomer of cyclohexane
b. Molecules with the formula `C_(6)H_(12)` that contain one ring and are enantiomers of each other.
c. Molecules with formula `C_(6)H_(12)` that contian one ring and are diastereomers of each other.
d. Molecules with formula `C_(6)H_(12)` that contain no ring and are enantiomers of each other.
e. Molecules with formula `C_(6)H_(12)` that contain no ring and are diastereomers of each other.
