To conclude the confidence level used to calculate the confidence interval.

Suppose that the population of the scores of all high school seniors who took the SAT math (SATM) test this year follows a normal distribution with standard deviation σ= 100.  You read a report that says, "On the basis of the simple random sample of 100 high school seniors that took the SATM test this year, a confidence interval for µ is found to be 512.00 ± 25.76."  What was the confidence level used to calculate this confidence interval?

A)      90%

B)      95%

C)      99%

D)     99.9%