After an ANOVA that compares four treatments, you calculate a separate two-sample t 95% confidence interval for each pairwise difference formed from the four population means. Are you 95% confident that these intervals capture all the true differences?
(a) No, because 95% confidence applies to each interval alone, not to all the intervals together.
(b) No, because the ordinary two-sample t confidence intervals cannot be used for a difference between two population means when we have data from other populations as well.
(c) Yes, because under the ANOVA conditions, following the t procedure gives correct 95% confidence intervals.