When would within groups ANOVA be appropriate?

In which situation would it be necessary to use a within-groups ANOVA? A researcher is interested in a longitudinal study that follows a group of kindergarten children through high school; he assesses their body mass index at four time points. A researcher interested in the effects of distraction on driving performance randomly assigns participants to one of three distraction groups. A researcher is interested in whether a sensitivity training class changes attitudes toward minority populations. The researcher assesses these attitudes in participants who have and have not had the sensitivity training class. O A researcher classifies a group of college students on the basis of their political leanings as liberal, conservative, libertarian, or green