What Does the Term "Diagnostic Overshadowing" Mean

What does the term "diagnostic overshadowing" mean?

A) Children with Intellectual Disability are treated primarily for their disruptive behavior problems rather than any possible internalizing disorders, such as depression and anxiety.
B) Children with very low IQ are diagnosed with learning disabilities instead of with Intellectual Disability.
C) The diagnosis of Intellectual Disability is often overlooked among people with other disorders.
D) Other disorders are often overlooked among people with Intellectual Disability.