I believe that the answer is c. but it could be d.
It is difficult for people with arthritis of the kness to A. Genuflect.
I would say that such a cruise ship would be an example of a supplier since on shore excursions presumably would be organized by the ship strictly for the ship passengers so this means the ship personnel would be the chief suppliers of this service.
You could start it with the following sentences....
What do you think of when you think of mass hysteria...? I think of__________.
Mass hysteria. That word sends shivers down my spine. Just think about it....(and then list things that would happen)
Close your eyes. Picture a place where,...(and then list other things that might happen)
