____________ the classroom, he found all the pupils sitting at their desks and revising their homework.
Помогите, хочу разобраться. К какому разделу грамматики относится? правильный ответ, и почему остальные не подходят.

Аноним: Participle clauses can be formed with the present participle (-ing form of the verb) or past participle (third form of the verb). Participle clauses with past participles have a passive meaning: Having come