Reference - Diving Fiasco

Reference - Diving Fiasco. Mike, who owns a dive shop in the U.S., decides to take a group of his customers diving in U.S. waters. Mike is aware that the area where the divers will be visiting is occasionally visited by sharks. He is also aware that, while sting rays are usually tame, they can become aggressive when fed. Mike does not reveal that information to the group of divers going with him. The divers go down into the water, and some have squid with which to feed the sting rays. During the dive, one of the sting rays becomes agitated and latches onto diver Susie's arm. Susie is so disconcerted that she drops her regulator (her breathing device) from her mouth and is in considerable difficulty. Another diver, Billy, encounters a shark which snaps at him. While the shark does not actually bite Billy himself, the attack results in damage to his diving equipment. Mike, who is in charge of the dive, does nothing to help and leaves the other divers to return to the boat because the dive turned out to be more trouble than expected. Wendy, another diver on the trip, also returns to the boat without doing anything to help the divers in distress. Sam, on the other hand, goes to rescue the divers who are in distress. He manages to do so but in the process he pulls his back and requires medical care. All divers are very unhappy with Mike. Billy and Susie are annoyed that Mike did not come to their assistance. Which is true regarding Mike's duty to provide assistance to them during the dive?

A) Mike had no duty to provide any assistance to them.
B) Mike had a duty to come to their aid because he arranged the dive and was charging them.
C) Mike had a duty to come to their assistance only if he had specifically agreed to do so prior to the dive.
D) Mike had a duty to come to their assistance only if they were minors.
E) Mike had a duty to come to their assistance only if no one else did so.