Final answer:
To find the nearest college offering a certain course in a MongoDB spatial database, the $near Sphere spatial operator is the best choice as it finds objects nearest to a point on a sphere, such as the Earth's surface.
Step-by-step explanation:
When querying a MongoDB spatial database to find the nearest college that runs a particular course, the most suitable spatial operator to use would be $nearSphere. This operator returns geospatial objects in proximity to a point on a sphere, which is useful for finding the nearest locations on Earth. It would be the ideal choice for locating the closest college offering a specific course. Operators like $Geo Intersects would be more appropriate if you needed to find colleges within a certain area, and $Geo Within returns colleges within a specified shape or boundary, which are not primarily used for finding the nearest location.