Neither the strong interaction nor electromagnetism permit flavour changing, so this must proceed by weak decay; without weak decay, quark properties such as strangeness and charm (associated with the quarks of the same name) would also be conserved across all interactions.
Neither the strong interaction nor electromagnetism permit flavour changing, so this must proceed by weak decay. Also, without weak decay the quark properties such as strangeness and charm (associated only with the quarks of the same name) would also be conserved across all interactions.