A developmental disability is primarily characterized as:

A developmental disability is primarily understood as a chronic disability that typically manifests during the developmental years, often recognized in childhood rather than adulthood. This classification includes a variety of conditions that may affect an individual's physical, learning, language, or behavioral abilities.

Choosing the option that describes it as a chronic disability identified in youth aligns with the common definitions and standards established in both legal and medical contexts. Developmental disabilities can significantly impact daily functioning and require ongoing support and intervention. This contrasts with conditions that are temporary or only identified in adulthood, which do not encompass the defining traits of developmental disabilities. Additionally, developmental disabilities are not solely due to environmental factors or considered manageable to the extent that they have minimal life impact — these areas indicate a misunderstanding of the scope and nature of such disabilities.