Respuesta :
Answer:
Correct answer is C. oil .
Explanation:
Option C is the only correct option as reasons for this drastic drop were pretty simple. During the 1980s the need for oil has been reduced, while on the other side the production has increased. Because of that the prices went down as it was impossible to sell all the oil that we had on the market.
All other options are false as the prices of this products didn't change drastically in that period,