5. Where does Mrs. Weigel buy vegetables?
Explanation: 'in dem Bioladen' means 'in the organic food store'. 'Bioladen' is a masculine noun. For a location (where), the dative case is used, hence 'in dem'. This can be contracted to 'im Bioladen'. The question provides '( = Bioladen )' suggesting a choice between prepositions and articles to fit the context.