Which of the Following Properly Describes Constitutional Isomers

Multiple Choice

Which of the following properly describes constitutional isomers?

A) organic compounds with different molecular formulas
B) compounds with the same molecular formula,but a different order of attachment of atoms
C) compounds with the same molecular formula and order of attachment of atoms,but a different spatial arrangement of atoms
D) compounds with the same number of hydrogens,but a different number of carbons
E) compounds with the same number of carbons,but a different number of hydrogens