= Solution
For comparable transition energies and ordinary single-particle nuclear strengths in the long-wavelength regime, the usual qualitative ordering is \b[$E1$, $M1$, $E2$, $M2$, $E3$, $M3$ from faster to slower]. Each increase of multipole order is strongly suppressed, and magnetic radiation is usually weaker than electric radiation of the same order. More precisely,
$$
\lambda(\sigma L)\propto E_\gamma^{2L+1}B(\sigma L),\qquad \sigma=E\text{ or }M.
$$
The nuclear reduced transition strength $B$ is essential: collective enhancement, cancellation and <selection rules> can overturn this benchmark. It is not a universal ranking between arbitrary transitions of different energies. The weak measured M3 branch is consistent with high-multipole suppression, but its absolute lifetime cannot be obtained from its arbitrary-unit <intensity> alone.<Guidelines for Nuclear Structure Evaluators by Murray J. Martin>[Appendix C, printed pp.60–67, transition rates and Weisskopf single-particle estimates]{ref}
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