Which legislation was signed into effect in 1966 to regulate who may possess or sell certain animals?

The Animal Welfare Act, signed into law in 1966, is significant legislation that establishes a set of regulations in the United States concerning the treatment and care of animals. This act was created to ensure that animals used in research, exhibition, and as pets are provided with humane living conditions and care. It outlines the standards for the handling and housing of certain animals, focusing on the humane treatment of animals in various contexts.

One of the key aspects of the Animal Welfare Act is its provision regarding the ownership and sale of animals, which includes requirements for licensing and inspections of facilities that breed, sell, or transport animals. This legislation is essential for protecting animals from neglect and abuse, thereby regulating who may lawfully possess or sell specific species, particularly those that are domesticated or commonly kept as pets.

The other pieces of legislation mentioned in the options serve different purposes. For example, the Lacey Act pertains to the conservation of wildlife by controlling the trade of animals and plants that are taken illegally, while the Endangered Species Act focuses on protecting species at risk of extinction and their habitats. The Wildlife Conservation Act primarily addresses wildlife management and conservation efforts.