Correct option is D
Explanation of the Correct Answer: · The sentence is in passive voice ("Stones were thrown").
· To convert to active voice, we need a subject → "They."
· The verb "were thrown" (past passive) changes to "threw" (past active).
· Correct active sentence:
· "They threw stones at the dog."
Why Are the Other Options Incorrect? · (a) "Had been throwing" → Incorrect; changes the tense.
· (b) "Throw stones" → Incorrect; changes past to present.
· (c) "Were throwing" → Incorrect; continuous tense is unnecessary.
Thus, the correct answer is (d) "They threw stones at the dog."