单选题：Questions are based on the following passage.The idea of

Questions are based on the following passage.
The idea of public works projects as a device to prevent or control depression was designed as means of creating job opportunities for unemployed workers and as a "pump priming" device to aid business to revive. It was conceived during the early year as of the New Deal Era (1933-1937). By 1933, the number of unemployed workers had reached about 13 million. This meant that about 50 million people--about one third of the nation--were without means of support. At first, direct relief in the form of cash or food was provided for these people. This made them recipients (接受者) of government charity. In order to remove this stigma (耻辱)and restore to the unemployed some measure of respectability and human dignity, a plan was devised to create governmentally sponsored work projects that private industry would not or could not provide. This would also stimulate production and revive business activity.
The best way to explain how this procedure is expected to work is to explain how it actually worked when it was first tried. The first experiment with it was the creation of the Works Project Administration (WPA).
This agency set up work projects in various fields in which there were many unemployed. For example,unemployed actors were organized into theater projects; orchestras were organized for unemployed musicians,teaching projects for unemployed teachers, and even writers' projects for unemployed writers. Unemployed laborers were put to building work or maintaining roads, parks, playgrounds, or public buildings. These were all temporary "work relief" projects rather than permanent work opportunities.
More substantial work projects of a permanent nature were organized by another agency, the Public Works Administration(PWA). This agency undertook the planning of construction of schools, houses, post offices, dams, and other public structures. It entered into contracts with private construction firms to erect them, or it loaned money to local or state governments which undertook their construction. This created many jobs in the factories producing the material as well as in the projects themselves, and greatly reduced the number of the unemployed.
Still another agency which provided work projects for the unemployed was the Civilian Conservation Corps
(CCC．. This agency provided job opportunities for youths aged 16 to 20 to work in national parks or forests clearing land, guarding against fires, building roads, or doing other conservation work. In the event of a future depression, the federal government might revive any or all of the above methods to relieve unemployment and stimulate business.
It was at the beginning of the New Deal Era that public works projects__________. A．were ignored by most American socialists
B．proved its advantages over other plans
C．were given a serious consideration
D．were put into use immediately