1) In “Fiesta, 1980,” Papi and Mami’s relationship is already strained. In what ways is this portrayed in the story??

it is used to emphasize the word or sentence.

the answer is:

a. american car ownership in the 1900s 1. (supporting detail).

in the outline, the example sentence that describes how many americans owned cars in 1900 and 1917 should be located in the body paragraph that speaks about car ownership in the 1900s. the reason is, the details with the number of citizens who owned cars in those times provide specif evidence to support the understanding of the paragraph.