What does the Clarke McNary Law provide for in addition to nursery stock aid?

The Clarke McNary Law, enacted in 1924, primarily aimed at promoting forestry and forest conservation across the United States. In addition to aiding nursery stock production, which was a crucial element of forest management, the law provided for further assistance in producing and propagating healthy seedlings. This enhancement in the production process was designed to ensure that there would be an adequate supply of quality trees for reforestation and afforestation efforts, thus supporting broader goals related to timber management and sustainable forestry practices.

The other options, while relevant to forestry and conservation, do not directly relate to the specific provisions of the Clarke McNary Law. Funding for forest education programs, regulatory controls on logging, and land acquisition for national parks represent different aspects of forestry management and conservation strategies that are not central to the objectives of the Clarke McNary Law as it pertains to nursery stock aid. The law is primarily concerned with improving seedling production, which aligns with the selected answer.