an important effect of the collective importance of wartime agencies was

a.it set a valuable precedent of government activism in the economy
b.it reduced the profits of America's largest corporations
c.it started a downturn in the number of workers in unions
d. it caused a recession in the agricultural economy
i think its a

I agree.

To determine the correct answer, let's analyze each option and explore the impact of wartime agencies during the specified period:

a) It set a valuable precedent of government activism in the economy: This option suggests that the collective importance of wartime agencies established a significant precedent for government intervention in the economy. During times of war, various agencies were created to coordinate and mobilize resources, regulate industries, and manage economic activities. These government interventions were seen as necessary to support the war effort and ensure the efficient allocation of resources. In this sense, the creation and functioning of these agencies did establish a precedent for government activism, making option a a plausible answer.

b) It reduced the profits of America's largest corporations: Although wartime agencies did exert control and regulate economic activities, it is not accurate to say that they directly reduced the profits of America's largest corporations. In fact, during wartime, many corporations benefited from increased demand for goods and services. Therefore, option b is unlikely to be the answer.

c) It started a downturn in the number of workers in unions: The impact of wartime agencies on unions and labor relations is more complex. On one hand, the agencies did implement labor policies aimed at preventing strikes and providing stability in the workforce to support war production. These policies may have contributed to a temporary decline in union activity during wartime. However, it would be an oversimplification to state that the collective importance of wartime agencies "started a downturn" in the number of workers in unions. Therefore, option c is not the correct answer.

d) It caused a recession in the agricultural economy: The collective importance of wartime agencies did not cause a recession specifically in the agricultural economy. While there were some challenges experienced by the agricultural sector during the war years due to changes in labor availability and resource allocation, it would be inaccurate to attribute a full-fledged recession solely to the wartime agencies. Hence, option d is unlikely to be the correct answer.

Based on the analysis above, it can be concluded that option a, "it set a valuable precedent of government activism in the economy," is the most accurate answer. The collective importance of wartime agencies did establish a precedent for increased government intervention in the economy, particularly during times of crisis.