下列随机变量中，（）服从自由度为n-1的t分布.A. t=(overline(X)-mu)/(S_(1)/sqrt(n-1))B. t=(overline(X)-mu)/(S_(2)/sqrt(n-1))C. t=(overline(X)-mu)/(S_(3)/sqrt(n))D. t=(overline(X)-mu)/(S_(4)/sqrt(n))

A. $t=\frac{\overline{X}-\mu}{S_{1}/\sqrt{n-1}}$

B. $t=\frac{\overline{X}-\mu}{S_{2}/\sqrt{n-1}}$

C. $t=\frac{\overline{X}-\mu}{S_{3}/\sqrt{n}}$

D. $t=\frac{\overline{X}-\mu}{S_{4}/\sqrt{n}}$