the answer is A. a sequence of events that lead to an accident.
steps
An accident chain is a series of events that lead to an accident. The first event in the chain is often a small mistake or error, but it can snowball into a larger accident if other events follow. For example, a driver may make a small mistake by not paying attention to the road, which could lead to them hitting the brakes too hard. This could cause the car to skid, which could then lead to the car hitting another car.
The other options are incorrect. Option B is a series of accidents happening around the same time, which is not what an accident chain is. Option C is a safety chain you wear to prevent accidents, which is not an accident chain. Option D is a list of accidents that cannot be avoided, which is also not an accident chain.