In the following question, a sentence has been given in Direct/Indirect speech. Out of the four alternatives suggested, select the one, which best express the same sentence in Indirect/Direct speech.The professor said to the students, 'Do not make a noise.'

The given direct sentence is an imperative sentence expressing a command/prohibition.When changing negative imperative sentences into Indirect speech:"said to" changes to "told" + object + "not to" + $V_1$.Alternatively, it can change to "forbade" + object + "to" + $V_1$ (or "from + $V_{ing}$ "), but the options must be evaluated for standard patterns.Let's look at the choices:Option B: "The professor told the students not to make a noise." follows the exact standard transformation rules perfectly.Option A uses "forbade... from making", which is less common than "forbade to make" and option B is the standard exact transformation for imperative sentences.Option D changes the reporting verb to present tense ("tells"), which is incorrect because the original reporting verb is "said" (past).Thus, Option B is the best answer.