. 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?