Answer
The strangeness conservation law is violated.
Work Step by Step
The $\Omega^-$ has strangeness $-3$
The $\Sigma^-$ has strangeness $-1$
The $\pi^0$ has strangeness $0$
Therefore, the strangeness conservation law is violated.
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.