Answer:
A. the relationship between a driver and the passengers in a car regarding the safe driving of that car
Step-by-step explanation:
As the driver is providing the service of pick and drop, and is regular in doing so, he is responsible for that.
Also generally cab drivers work through an organization for example UBER which assures the quality of driving and safety.
Thus, with this third party confirmation and assurance there are least chances to get a conflict about the quality of driving in between the passenger and the driver.