Nathan is run over by a car and left lying in the street. Sam, seeing Nathan's helpless state, places him in his car to take him to the hospital. Sam drives negligently into a ditch, causing additional injury to Nathan. Is Sam liable to Nathan?

Yes, for all of the injuries because he volunteered to help and that makes him liable.

Yes, for the additional injuries because he did not take reasonable care.

No$,$ because the accident was only a superseding cause.

No$,$ because he did not have a duty to help.