A reference in this Part to a person's disability is a reference to a disability--
(a) that a person has, or
(b) that a person is thought to have (whether or not the person in fact has the disability), or
(c) that a person had in the past, or is thought to have had in the past (whether or not the person in fact had the disability), or
(d) that a person will have in the future, or that it is thought a person will have in the future (whether or not the person in fact will have the disability).