The daily revenue from the sale of fried dough at a local street vendor in Boston is known to be normally distributed with a known standard deviation of $120. The revenue on each of the last 25 days is noted, and the average is computed as $550. A 95% confidence interval is constructed for the population mean revenue. If the data from the last 40 days had been used, then the resulting 95% confidence intervals would have been . Select one:
a. wider confidence interval, with the same probability of reporting an incorrect interval
b. narrower confidence interval, with a larger probability of reporting an incorrect interval
c. narrower confidence interval, with the same probability of reporting an incorrect interval
d. wider confidence interval, with a larger probability of reporting an incorrect interval