==> In the original condition, there is 1 variable. In order to match the number of variables to the number of equations, there must be 1 equation. Since there is 1 for con 1) and 1 for con 2), D is most likely to be the answer. For con 1), n=2 no, n=12 yes, hence it is not sufficient.

For con 2), n=24t(t=any positive integer), hence it is always yes and sufficient.

Therefore, the answer is B.

Answer: B

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