Which act amended PL 94-142 to include preschool age children and focused on early intervention?

The correct answer is PL 99-457, which is significant because it specifically amended the Education for All Handicapped Children Act (originally PL 94-142) to expand services to preschool-aged children. This amendment recognized the importance of early intervention and the need for educational services for young children with disabilities. The focus on early intervention is crucial as it lays the foundation for better educational outcomes, helping to address developmental delays as early as possible.

PL 99-457 not only provided funding for states to develop early childhood programs but also required that children with disabilities aged 3 to 5 receive free and appropriate public education. By including preschoolers, the law emphasized the critical period of early childhood development and the importance of integrating these young learners into educational settings, thereby promoting their effective growth and learning.

The other laws mentioned play essential roles in protecting the rights of individuals with disabilities and ensuring access to various services, but none specifically focus on the amendment to include preschool-age children within the educational system as PL 99-457 does.