Answer:
D. A force within a fluid that pushes upward
Step-by-step explanation:
Buoyancy is the ability of something floating in water, so it's probably not about the attraction between molecules and is about a force within a fluid. If a force within a fluid is pushing downwards on an object, that would make the object go downwards (sink), which is not buoyancy. If a force within a fluid is pushing upwards on an object, the object would be floating.