Determine the change in strangeness in each reaction that follows, and state whether the reaction can proceed via the strong interaction, the weak interaction, or not at all:

(a) Ω^– → Ξ⁰ + π^–,

(b) Ξ⁰ → p + π^– + π⁰Ξ, and

(c) Λ⁰ → p⁺ + π^–.