Two players wrote with objections to how the answers were scored. Here are their comments:
My response: I can see why these players were caught up on this issue, but I believe it results from a mis-reading of the quiz question, which ends with:
Notice that I say "call the hr.plch_pkg.language_vendor function repeatedly". The g_language variable (which gives "state" to the package, leading to the ORA-04068 error) is not used by the language_vendor function. Changing the value of this variable does not affect this function in any way. So I don't think this statement is true: "The new package body should reference the variable declared in plch_pkg_constant."
Of course, in the "real world", it is unlikely that you can move a variable from one package to another without having a ripple effect through other subprograms and program units. But I don't think that is an issue here.