B.their uses for medicinal purposes I think. Not 100% sure.
The correct answer is D. water parks.
Water parks started their construction during the late 1940s, so obviously people couldn't enjoy them prior to that moment. Coney island began building in 1840s, Barnum and Bailey circus was there since 1870s, and Nickelodeons (referring to cinemas) were there since late 1800s.
Answer:
The stock market crashed.
It makes products cheaper for consumers to buy.
