Understand the concept of inclusive education.

Inclusive education aims to ensure that all students, regardless of their abilities or disabilities, learn together in the same general education classrooms. It focuses on providing equal opportunities and support for all learners to participate and succeed.

• A. "Allowing learners with special needs to learn and interact with learners without needs." This aligns with the core principle of inclusive education, which is about integrating students with special needs into mainstream settings alongside their peers.
• B. "Educating persons with mental illness in special education institutions." This describes a segregated approach, where students with specific needs are educated in separate institutions, which is contrary to the concept of inclusion.
• C. "Providing special assistance by special education experts to persons with special needs." While special assistance is a part of inclusive education, this option doesn't specify that this assistance occurs within an inclusive setting alongside other learners. It could still imply a segregated approach.
• D. "Training persons with special needs through rehabilitation in special education Institutions." This also describes a segregated approach focused on rehabilitation rather than general education inclusion.

Option A most accurately describes inclusive education by emphasizing the learning and interaction of all students together, regardless of their needs.

The final answer is $\boxed{\text{A}}$