Answer
114.7 MeV
Work Step by Step
The energy released is the difference in the mass energy between the initial particle(s) and the final particle(s). The energy released is positive if the initial particle(s) has/have more energy.
The $\Sigma^o$ eventually decays to a proton and a $\pi^-$.
$$E_{release}=m_{\Sigma^o}c^2- m_{p}c^2- m_{\pi^-}c^2$$
$$E_{release}=1192.6.6 MeV-938.3MeV-139.6MeV=114.7MeV$$