Read the sentence below to find out whether there is any grammatical error in it. The error, if any, will be in one part of the sentence. Choose the option with that part as your answer. If there is no error, choose 'D' as your answer. (Ignore the errors of punctuation, if any).
On the busy Ring Road, we witnessed a collusion between a truck and an auto.
On the busy Ring Road
we witnessed a collusion
between a truck and an auto.
No error.
Correct answer is B
we witnessed a collision