Which sentence is grammatically incorrect according to the text?

Ответ (EN)

The grammatically incorrect sentence is: "c. Did you saw" in question 11.

The correct form is "Did you see" or "Have you seen".

Перевод (RU)

Грамматически неверное предложение: "c. Did you saw" в вопросе 11.

Правильная форма: "Did you see" или "Have you seen".