Explanation: To create an audience based on complex criteria such as engagement and location, NTO should use SQL Queries5. SQL Queries allow NTO to write custom queries that can join data from different data extensions and filter based on various conditions5. Measures are used to define engagement metrics such as opens and clicks, but they cannot be used to filter by location or combine with other criteria5. Data Filters are used to filter data based on simple criteria such as attributes or measures, but they cannot be used to join data from different sources or filter by location5. Journey is used to create personalized customer journeys based on triggers and activities, but it is not a tool for creating audiences5.