During the 1970s when inflation accelerated, middle-class americans benefited primarily because

The value of their mortgage debts decreased in real terms.

Explanation:

Inflation refers to a measure of the rate at which the average price of certain goods and services in an economy increases over time. This means that the general level of prices is in rise, and a unit of currency buys less than it did before. This is also expressed as the loss in the purchasing power of a currency. However, inflation can also benefit some members of society. During the 1970s, inflation benefitted middle-class Americans because the value of their mortgage debts decreased in real terms.

c  

explanation:

the tariff was created to protect industry in the northern part of the united states. industries in the north were being driven out of business by imported goods that were priced at a low rate. the goal was to protect these industries   by taxing the goods.