It's like people would rather trust what they perceive an authority is telling them (even if there is a possibility that they misunderstood) than trust to avoid common sense (how could gravity drop off so quickly by distance and there still be a moon farther out?).
It's really a statement about whether people have learned to think scientifically. It's okay to have uncertainty about a hypothesis that has so far held up to experimental tests, but you should probably abandon hypotheses that have been rejected experimentally.
I think that's probably the case for a lot of people who choose (b) -- maybe enough to ask a second question about the understanding of why (b) is the case. But I bet a lot of people would choose (a) despite the clear evidence against it (e.g., the existence of satellites).
Falling is a type of movement
"motion" is pretty broad, as is "around" ("Go around the block" doesn't mean to move in a circle). But I see that my point was somehow lost in your case to concision enforced by character length and common sense, and I apologize for my failure.
Sadly, it's probably necessary to have such an option for people... Or one that says it's all fake.
I guess I should have said "falls under"...
I think that fits under (b)
It would be interesting to survey a large group of randomly sampled adults to ask: What is the primary reason why things on the space station experience near-zero gravity? Because of: (a) *distance from earth* (b) *motion around the earth* ? What do most people take from their #scienceEducation? 🧪