The answer is (1) because of its value as trading center ect
One of the most significant factors that led to the increase in the number of Latin Americans in the middle class in the late 19th century was the revolutions that took place around 1848, since these were initiated by primarily lower class people looking for a stronger socio-economic standing.
The development of the automotive industry has opened many jobs worldwide, including in the USA.
The automotive industry has a vast production chain, involving the plastics, steel, and car components industries. In this sense, besides the direct jobs, there is a great indirect employability.
In this context, the popularization of automobiles has increased the contingent of workers in related industries, as described in the third alternative (C).