Answer (EN)
- 4. The little boy asked his parents what they had bought him for Christmas.
Translation (RU)
- 4. Маленький мальчик спросил своих родителей, что они купили ему на Рождество.
Brief Explanation: Wh-questions in reported speech retain the wh-word but change the word order to subject-verb. The tense shifts back: 'have you bought' (present perfect) becomes 'had bought' (past perfect).