Given below is a sentence that may or may not be grammatically viable, choose the most suitable alternative that reflects the grammatically correct sentence. If the sentence does not require any correction, choose option 5, i.e., "no correction required" as your answer choice.
Many of the petrol bunks were automated over last three years.
1
Many of the petrol bunks was automated over last three years.
2
Many of the petrol bunks was automated over the last three years.
3
Many of the petrol bunks were automated over the last three years.
4
Many of the petrol bunks were automated for the last three years.
5
No correction required