What spatial query keeps only the road lines that divide cities selected from all Road Lines features?

Choosing the option that involves selecting from the currently selected features in City Polygons that completely contain the Road Lines is appropriate for the given spatial query. This is because the task requires filtering road lines based on their relationship to the selected city boundaries.

The phrase "divide cities" indicates that the focus is on identifying road lines that intersect or possibly are entirely within the area covered by city polygons. Therefore, selecting those city features that completely contain segments of the road lines is a logical step to ensure that the resulting selection specifically pertains to the road segments that separate or outline the urban areas defined by the city polygons.

This option accurately captures the essence of the query by ensuring that only those roads which interact with or are surrounded by the city boundaries are kept, fulfilling the intention of the original spatial requirement.