Find the odd man out\n1, 3, 7, 11, 15, 18, 21\nOptions:\n(A) 3\n(B) 7\n(C) 18\n(D) 21\n(E) 1
Please answer the following question by reasoning step-by-step.
(C)
The 18 is the only even number in the series.

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So, the answer is (C)