(1) Subject to this Act, a widow, widower or surviving civil partner shall be entitled to a pension -

(a) where the contribution conditions set out in section 125 are satisfied on either the insurance record of the widow, widower or surviving civil partner or that of his or her deceased spouse or deceased civil partner,

(b) where the widow’s or widower’s spouse or surviving civil partner’s civil partner was entitled to a State pension (contributory) or a State pension (transition) which included an increase in respect of him or her by virtue of section 112(1) or 117(1) in respect of a period ending on the spouse’s or civil partner’s death, or