What was prohibited by Congress in 1905 regarding aquatic weed control?

The prohibition enacted by Congress in 1905 focused on the use of any chemical that could be injurious to cattle or humans. This reflects an important aspect of environmental regulation, emphasizing the need to protect both public health and the welfare of livestock from harmful substances. At that time, the introduction of certain chemicals for aquatic weed control could have posed significant risks to both human populations and agricultural animals. The development of regulations during this period aimed to ensure that any methods used for such control did not inadvertently harm those who interacted with the affected environments.

The other options relate to concepts in aquatic weed control, but they do not reflect the specific prohibition established in 1905. Mechanical removal methods, the introduction of non-native species, and biological control agents have all been subjects of regulation and debate, but they were not the focus of the early legislative measures taken to safeguard human and animal health concerning chemical use. Thus, option B stands as the correct answer, highlighting the importance of safety in pest management practices.