Answer :
The sentence '_______cum advenisti?' is best completed with the word 'Quibus', which is the dative plural of 'qui', 'quae', 'quod' and makes sense in a given context that calls for an expression of association with the action.
To best complete the sentence "_______cum advenisti?" given the options, the correct word is Quibus. This is because this sentence seemingly requires the dative plural of qui, quae, quod (who, which), to make sense in context, matching a possible dative use that expresses an association with the action. For example, the sentence could mean 'With whom did you come?' or 'By what means did you arrive?', though without further context, one cannot determine the exact meaning. Thus, Quibus is the best fit for the blank.
