Correct Answer: “Go straight to your classrooms,” the teacher said to the students.

Solution : The correct option is the fourth option.

Direct speech is when someone's exact words are quoted within quotation marks. It usually maintains the tense and structure of the original sentence.

Narration Conversion:

• Ordered is changed to the reporting verb said, as the words are directly quoted.
• Their (third-person pronoun) is changed to your (second-person pronoun) in the direct speech.
• The reported clause, go straight to your classrooms is directly quoted.

Therefore, the direct speech is: " Go straight to your classrooms," the teacher said to the students.