Помогите. Задайте общий вопрос к следующим предложениям: The workers installed the X-rays unit at the plant.

Выберите один ответ:

a.
​ Do the workers installed the X-rays unit at the plant?


b.
​ Installed the workers the X-rays unit at the plant?


c.
​ Did the workers installed the X-rays unit at the plant?


d.
​ Did the workers install the X-rays unit at the plant?