Use and internet search engine to find a development in any areas of science during the past 10 years

Each year, Science’s editors choose a singular scientific achievement as Breakthrough of the Year. Past winners have included the discovery of the Higgs boson, cancer immunotherapy, and the first quantum machine. This year’s winner captured the world’s attention and reminded us of the immense scope of human scientific accomplishment—as well as how far we have yet to go. Below we briefly summarize the winner and runners-up and link to the expanded stories, with references, in the magazine, which are freely available.

Explanation:

the answer is d. tariffs were raised by america's trading partners after the smoot-hawley tariff act, decreasing exports, and declining job rates.