In the view of many historians, which republican economic medicine of the 1920s cause the sickness of depression during the 1930s a. increased tariffs b. immigration restriction c. the agricultural marketing act of 1929 d. federal regulation

I think it’s D :)...

A. Increased tariffs

Explanation:

The Great Depression of the 1930s was the largest recession in history and its causes were overproduction of goods and the expansion of unbridled credit by banks.

Initially the republican President Herbert Hoover chose not to intervene. Meanwhile, with the escalating damage from the crisis, the president has taken some punctual measures to combat the Great Depression, such as providing minimal social assistance and regulating the market. However, Hoover also took measures that worsened the Great Depression, such as raising taxes and increasing tariffs. As a consequence, other nations also impacted by the crisis have adopted measures of protectionism, worsening the situation of international trade and the economy as a whole

i am pretty sure the awsers is d.

the answer is mass marketing.