What is a characteristic of intellectual disability?

C is the characteristic of intellectual disability that recognizes the possibility of its onset due to factors such as brain injuries that occur before full cognitive development. Intellectual disabilities can arise not only from genetic conditions but also from environmental influences and damage during critical developmental periods. This highlights the complexity of intellectual disability, encompassing both genetic predispositions and experiences related to injury or environment.

The other choices do not accurately represent the broader understanding of intellectual disabilities. Diagnosis does not only happen in adulthood; many cases are identified in childhood. While genetic factors contribute to some instances of intellectual disability, they are not the sole cause, as numerous environmental conditions can also play a role. Finally, treatment for intellectual disabilities typically involves a multidisciplinary approach, incorporating various therapies, educational interventions, and support mechanisms alongside any necessary medications, rather than relying solely on pharmacological treatment.