[Diving Fiasco] Rogerio, Who Owns a Dive Shop in the U.S

[Diving Fiasco] Rogerio, who owns a dive shop in the U.S., takes a group of his customers diving in U.S. waters. Rogerio 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. Rogerio did not reveal the information about sharks or sting rays to the group of divers going with him because, in his experience, as soon as customers hear of a hint of danger, they refuse to pay and go on the trip. 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 lashes diver Tamika's arm. Tamika is so disconcerted that she drops her regulator (breathing device) from her mouth and is in considerable distress. Another diver, Billy, encounters a shark which snaps at him. Fortunately, the shark does not bite him but does damage his diving equipment. He is also in distress. Rogerio, who is in charge of the dive, does nothing and just returns to the boat because the dive turned out to be more trouble than expected. Claudia, 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 assist them, but in the process, he injures his back and requires medical care. All divers return to the boat and are very unhappy with Rogerio.
-Did Rogerio have a duty to provide assistance to Tamika and Billy during the dive?

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