Answer
This process can not proceed via the strong interaction.
Work Step by Step
The $\Lambda^0$ has strangeness $-1$
The proton $p$ has strangeness $0$
The $\pi^-$ has strangeness $0$
The net strangeness of the left side of the process is $-1$
The net strangeness of the right side of the process is $0$
Since strangeness is not conserved in this process, this process can not proceed via the strong interaction.
