Friend wants to take one for the team, how do I tell which OS comes on refurb mini?

[Chakravartin]

Filliam H. Muffman wrote:
Sorry, I didn't get a lot of sleep last night, I was trying to figure out which mini ships with which OS. Does it default to the OS that first shipped with a specific model?

Consider ML the earliest OS you are likely to find installed on any refurb Mac from Apple at this point.

(And you're not likely to find a 2011 Mini in stock at the refurb store.)