What is the difference between related services and supplementary aids and services in an IEP?

What is the difference between related services and supplementary aids and services in an IEP?

• A. Related services are services to improve core academic skills; supplementary aids are supports to access the general curriculum.
• B. Related services are optional; supplementary aids are mandatory.
• C. Related services are the same as supplementary aids.
• D. Related services are specialized services (e.g., speech therapy); supplementary aids and services are supports to access the general curriculum (e.g., adapted materials, assistive tech).

Answer: (D)