**Core Concept**
Mental retardation is a neurodevelopmental disorder characterized by significant cognitive and adaptive deficits, previously referred to by a term now considered outdated and stigmatizing.

**Why the Correct Answer is Right**
The American Association of Intellectual and Developmental Disabilities (AAIDD) has officially changed the terminology to "intellectual disability," reflecting a shift in understanding and promoting a more person-centered approach. This change aims to reduce stigma and improve the lives of individuals with intellectual disabilities. The term "intellectual disability" is defined by significant limitations in both intellectual functioning (as measured by IQ scores) and adaptive behavior, which covers everyday social and practical skills.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it is not recognized by the American Association of Intellectual and Developmental Disabilities (AAIDD) or other international organizations as a preferred term for the condition.
**Option B:** This option is incorrect as it is a term still used in some contexts, but not preferred by the AAIDD or other organizations, which emphasize the importance of using person-centered language.

**Clinical Pearl / High-Yield Fact**
It is essential for healthcare professionals to use person-centered language when communicating with individuals with intellectual disabilities and their families, focusing on their strengths and abilities rather than their limitations.

**Correct Answer:** C. Intellectual Disability