I've found a mock essay question in the practice bank but there's no answer available:(

"The price of oil dropped from $110 a barrel in June 2014 to about $30 a barrel in January 2016, a decrease of more than 70 percent over an 18-month period. It has since recovered but, at about $60 a barrel, its current price is still about 50 percent lower than in 2014. A drop of this size in the price of such an important commodity should have a significant impact on the economies of both oil-importing and oil-exporting countries. Indeed, due to such a rapid and sizeable change in relative prices, some countries and sectors might have been big winners while others might have been big losers. As an important producer and exporter of oil, what was the impact for Canada? Was the period of high oil-price definitely "good" for Canada? Is the current (relatively) low oil-price definitely "bad" for Canada?"

Question: What policies could be implemented to avoid the negative externalities of commodity-cycles?

May I ask that what points should I talk about in this paper? (Other than talking about how the decreasing oil price would affect the economy, should I also explain "negative externality" and "commodity cycles"?

If someone can confirm the key points and the structure of the essay I would appreciate.