Official Solution:
In the original condition, there is 1 variable \((x)\). In order to match the number of variables to the number of equations, there must be 1 equation. Therefore, D is most likely to be the answer.
In the case of con 1), if \(x = 2\), 6 is not a factor of 2, so no, and if \(x = 6\), you get yes, hence it is not sufficient.
In the case of con 2), from \(x^{2} = 12t\) (\(t\)=any positive integer), you should get \(x = \sqrt{12t} = \sqrt{12(12s^{2})}\) (\(s\)=any positive integer). That is because it is said that \(x\) is a positive integer, so \(x\) should always get rid of the root. If so, from \(x=\sqrt{12(12s^{2})} = \sqrt{12^{2}s^{2}} = \sqrt{(12s)^{2}} = 12s=6(2s)\), 6 is always a factor of \(x\), hence yes, and sufficient. The answer is B.
Answer: B