Which one of the following is the correct indirect speech of: The teacher said to the students, "Submit your assignments before the bell rings."
- AThe teacher told the students that they should submit their assignments before the bell rings.
- BThe teacher asked the students whether they submitted their assignments before the bell rang.
- CThe teacher said to the students to submit their assignments before the bell rang.
- DThe teacher ordered the students to submit their assignments before the bell rang.
Correct answer: D