They all have in common that they work with people either in phone or directly with them as costumers. Hence, working with people will be the answer
I would chose heart health because many people don't know all the things that can cause heart disease. And to be as wide spread as it is people need to know how important heart health is.
Answer:
communication
Explanation:
because all of the whole world can use them
it would go under the pfs history
