The correct answer is: D. No error
The sentence is grammatically correct. The word “collusion” is a noun that means “an agreement between two or more people to deceive others.” In this sentence, it is used to describe the accident that the speaker witnessed. The word “between” is a preposition that is used to show the relationship between two things. In this sentence, it is used to show the relationship between the truck and the auto that were involved in the accident. The word “auto”
is a noun that means “a small car.” In this sentence, it is used to describe the type of vehicle that was involved in the accident.The other options are incorrect because they contain grammatical errors. Option A is incorrect because it does not use a comma after the prepositional phrase “On the busy Ring Road.” Option B is incorrect because it does not use a verb after the subject “we.” Option C is incorrect because it does not use a preposition after the noun “collusion.”