Explanation:

Explanation:
 Invisible Disability, is an umbrella term that captures a whole spectrum of hidden disabilities that are not immediately apparent to other people. People with invisible disabilities are often accused of faking or imagining their disabilities. Recently, UK Government,
acknowledging “invisible disabilities” for the first time, allowed people with dementia or anxiety disorders to park their cars closer to their final destination (Blue Badge scheme of Department of Transport).
 Mental illness like depression, schizophrenia, dementia, attention deficit disorder and anxiety can make performing everyday tasks extremely difficult and so qualify for disability benefits.  Chronic Back Pain and Chronic Fatigue (that doesn’t improve with bed rest) can also be completely debilitating to the victim and so qualify for disability benefits. Invisible disability can also include sleep disorders if they significantly impair normal activities of daily living. So sleep disorders do not necessarily constitute invisible disability.  Hence, medical conditions 2, 3, 4 are the correct answer.