The two circles in the following picture include two sets of numbers. I think that each set should represent a certain pattern. Now the question is what the pattern might be. To tell the truth, this is a question from an exercise book. I'm not asking people here to solve exercise questions for me. I've thought real hard and tried every possibility I could think of. Thank you very much indeed.
My idea: The set on the left is a sample of prime numbers, and the set on the right is a sample of composite numbers. Only one of the answer options is a composite number.