1. Regulations may make provision—
(a)for a person to be treated in prescribed circumstances as having, or as not having, limited capability for work;
(b)for the question of whether a person has limited capability for work to be determined notwithstanding that he is for the time being treated by virtue of regulations under sub-paragraph (a) as having limited capability for work;
(c)for the question of whether a person has limited capability for work to be determined afresh in prescribed circumstances.