Correct answer: bicyclo[3,2,1]-octan-2-oic acid
In bicyclic nomenclature, the bridge lengths are written in descending order, giving bicyclo[3.2.1]octane as the parent framework. The carboxylic acid group is assigned the lowest possible position, which here is carbon 2, so the correct name is bicyclo[3,2,1]-octan-2-oic acid.