Four research teams each used a different method to collect data on how fast a new iron skillet rusts. assume that they all agree on the sample size and the sample mean (in minutes). use the (confidence level; confidence interval) pairs below to select the team that has the smallest sample standard deviation.
a. confidence level: 95% ; confidence interval: 40 to 50
b. confidence level: 99.7% ; confidence interval: 42 to 48
c. confidence level: 95% ; confidence interval: 35 to 55
d. confidence level: 68% ; confidence interval: 44.5 to 45.5