One of the economic activities of the Caribbean, as exemplified by institutions in Anguilla, Antigua and Barbuda, Montserrat, St. Kitts and Nevis, as well as many other Caribbean countries and non-independent territories, are the presence of _____. People who go to these institutions often do so as a "second choice" alternative.
a. Cancer treatment centers
b. Gambling addiction recovery centers
c. Curative, or "chemically healthy" hot springs
d. Herbal, holistic, and organic health centers