“a nigerian tariff on car imports aimed at boosting local production has reduced the number of vehicles brought into the country this year by a quarter and fuelled smuggling from neighboring benin, the ports authority said. car imports fell to 70,453 units in the first 10 months of this year (2017), a 26.8 percent reduction on the same period of 2016, nigerian ports authority (npa) figures showed. the government imposed a 70 percent tariff on imported vehicles in december 2015 as part of attempts by president muhammadu buhari to stimulate local production.” - from “nigeria tariff causes car imports to fall, fuels smuggling - ports authority,” reuters, december 15, 2017 the main topic of this article centers around a) trade barriers. b) specialization. c) embargoes and quotas. d) environmental regulations.

when studying cause and effect, historians usually group the causes into different categories. for example, cultural causes reflect how a society’s literature and art convey the way the society saw itself in relation to the rest of the world. another resource that historians use to understand society is pop culture, which tells them the trends and ideas that are preferred by the common people. when studying cause and effect, it’s important to remember multiple causation, or the idea that an effect could have several causes and vice versa.  

the correct option is “cultural causes” since art and literature are related to the culture of a place. culture is determined by literature, art, music.

the correct option is “pop culture” since it reflects the likes and ideas of common people whereas the rest of the options do not focus on common people.  

the correct option is “multiple causation” since it refers to the idea that events are caused by multiple reasons, not just a single one.  

the answer is a) high entry costs