nucleus information and low T orientation

1) You can infer that it is a nucleus with spin I = 1. The splitting in 3 levels can be explained by the magnetic dipole interaction which immediately splits them in all scenario’s, but the electric quadrupole operator can also split all levels of an integer-spin nucleus if it is deformed. Or it can be explained by a combination of the two. This means it has at least one non-vanishing interaction between the magnetic dipole interaction and the electric quadrupole interaction.
2) At low temperature almost no thermal excitation to higher states will be possible. This means quasi all nuclei in the ensemble will remain in the the ground state, resulting in an ensemble with polarization in the positive z-direction for this example.