Explanation:

- The study by Vogel and Bell explores how children can be used as emotional scapegoats by parents to relieve their tension.

- Option 1: African families – This option suggests the study focused on African families; however, that is not the correct context.

- Option 2: American families – This option is correct. The study by Vogel and Bell examined the dynamics within American families, where children can often become the emotional outlet for parental tensions.

- Option 3: Island of West Indies – This option suggests the study was about West Indian families, which is incorrect in this context.

- Option 4: European families – Suggests focus on families in Europe, yet not the focal point of this study.