A 10-year-old boy displays deficits in intellectual functions that involve his ability to reason, solve problems, and learn from instruction or experience. He has been slow to develop skills in school and is behind his peers in reading, writing, and mathematical abilities. As a result, he has significant impairments in his ability to develop socially appropriate interpersonal communication skills and has developed no real friendships. He is dependent on others for assistance with his basic needs, such as dressing and feeding. Which of the following diagnoses most accurately represents this presentation?

Choice A reason: Autism spectrum disorder primarily involves deficits in social communication and restricted/repetitive behaviors. While some overlap exists, the primary issue here is broad cognitive impairment affecting adaptive functioning, which is more consistent with intellectual disability. Choice B reason: Global developmental delay applies to children under age 5 with delays in multiple developmental domains. At age 10, this diagnosis is no longer appropriate; intellectual disability is diagnosed instead. Choice C reason: This choice is correct because intellectual disability is defined by deficits in intellectual functioning (reasoning, problem-solving, learning) and adaptive functioning (communication, social participation, daily living skills). The description matches both criteria. Choice D reason: Childhood-onset neurocognitive disorder is generally reserved for disorders like early-onset dementia or acquired cognitive impairments, not congenital or developmental intellectual deficits.