Periods during which right to buy is preserved
5A. A period qualifies under this paragraph if it is a period during which, before the relevant time—
(a)the qualifying person, or
(b)his spouse (if they are living together at the relevant time), or
(c)a deceased spouse of his (if they were living together at the time of the death),
was a qualifying person for the purposes of the preserved right to buy or was the spouse of such a person and occupied the qualifying dwelling-house as his only or principal home.