The Energy of a Magnetic Dipole in an External Magnetic

The energy of a magnetic dipole in an external magnetic field is least when:

A) the dipole moment is parallel to the field
B) the dipole moment is antiparallel to the field
C) the dipole moment is perpendicular to the field
D) none of the above (the same energy is associated with all orientations)
E) none of the above (no energy is associated with the dipole-field interaction)