Which of the following statements correctly distinguishes between stereoisomers, constitutional isomers, and different conformations?
A) Stereoisomers have the same connectivity of atoms but differ in spatial arrangement; constitutional isomers differ in connectivity; different conformations are variations of the same molecule due to rotation around single bonds.
B) Constitutional isomers have the same connectivity of atoms but differ in spatial arrangement; stereoisomers differ in connectivity; different conformations are variations due to changes in the molecule's functional groups.
C) Stereoisomers differ in connectivity of atoms; constitutional isomers differ in spatial arrangement; different conformations result from changes in the functional groups.
D) Constitutional isomers are identical molecules with different spatial arrangements; stereoisomers are the same molecule with different functional groups; different conformations are due to isotopic differences.