B requires only 1 body
C same as B
D does not require motion
Leaving A as the only answer that can satisfy the specified conditionsSource(s): ‘How often have I said to you that when you have eliminated the impossible, whatever remains,however improbable, must be the truth?’
Sherlock Holmes Quote
I don’t think A since it doesn’t say they are in contact.
I don’t think B or C since it doesn’t say they are rotating.
Gravitational force exists between any 2 bodies no matter what.
best available option: frictional… if the bodies are in contact