参考答案：B

解析：

We can construct a confidence interval by adding and subtracting some amount from the point estimate. In general, confidence intervals have the following form. Point estimate + Reliability factor x Standard error Point estimate = the value of a sample statistic of the population parameter Reliability factor = a number that depends on the sampling distribution of the point estimate and the probability the point estimate falls in the confidence interval (1-α) Standard error = the standard error of the point estimate