Mother said to me, "Did you spread the rumour?" (Make it Indirect) ?

The correct choice, C: "Mother asked me whether I had spread the rumour," accurately translates the direct speech into indirect speech by maintaining the original meaning and correct grammatical structure.

In direct speech, the speaker's exact words are quoted, while indirect speech involves paraphrasing those words without quotation marks. Here, the direct question, "Did you spread the rumour?" is transformed into a statement format in indirect speech.

Firstly, "asked" is the correct verb for reporting questions. The conversion from a question to indirect speech also necessitates changing the tense: "Did you spread" (simple past in direct speech) is shifted to "had spread" (past perfect in indirect speech) to reflect the sequence of events accurately.

Additionally, the use of "whether" instead of "if" is often more formal and is preferred in certain contexts, especially in written English and formal speech. Lastly, choice D contains a grammatical error with the word "spreaded," which is not a correct form of the verb "spread." This further reinforces that option C is the best choice as it adheres to grammatical rules and accurately conveys the meaning of the original statement.