Where is the "stock" translation?
"myydä" = sell, retail, vend, peddle, stock.
"Olemme pahoillamme, mutta me emme myy tuota kokoa" should be marked as also correct.
Should be "Pahoittelumme" instead of "Olemme pahoillamme" to match the english variant "Our apologies"
It should be accepted as an alternative in my opinion, but I do think "olemme pahoillamme" as an expression is much more common than "pahoittelumme", and is therefore a good translation.