The widow (as defined in section 416(c) of this title ) and every surviving divorced wife (as defined in section 416(d) of this title ) of an individual who died a fully insured individual, if such widow or such surviving divorced wife—

(A) is not married,

(B) (i) has attained age 60, or (ii) has attained age 50 but has not attained age 60 and is under a disability (as defined in section 423(d) of this title ) which began before the end of the period specified in paragraph (4),

(C) (i) has filed application for widow’s insurance benefits, (ii) was entitled to wife’s insurance benefits, on the basis of the wages and self-employment income of such individual, for the month preceding the month in which such individual died, and— (I) has attained retirement age (as defined in section 416( l ) of this title), (II) is not entitled to benefits under subsection (a) or section 423 of this title , or (III) has in effect a certificate (described in paragraph (8)) filed by her with the Commissioner of Social Security, in accordance with regulations prescribed by the Commissioner of Social Security, in which she elects to receive widow’s insurance benefits (subject to reduction as provided in subsection (q)), or (iii) was entitled, on the basis of such wages and self-employment income, to mother’s insurance benefits for the month preceding the month in which she attained retirement age (as defined in section 416( l ) of this title), and

(D) is not entitled to old-age insurance benefits or is entitled to old-age insurance benefits each of which is less than the primary insurance amount (as determined after application of subparagraphs (B) and (C) of paragraph (2)) of such deceased individual,

shall be entitled to a widow’s insurance benefit for each month, beginning with—

(E) if she satisfies subparagraph (B) by reason of clause (i) thereof, the first month in which she becomes so entitled to such insurance benefits, or

(F) if she satisfies subparagraph (B) by reason of clause (ii) thereof— (i) the first month after her waiting period (as defined in paragraph (5)) in which she becomes so entitled to such insurance benefits, or (ii) the first month during all of which she is under a disability and in which she becomes so entitled to such insurance benefits, but only if she was previously entitled to insurance benefits under this subsection on the basis of being under a disability and such first month occurs (I) in the period specified in paragraph (4) and (II) after the month in which a previous entitlement to such benefits on such basis terminated,

and ending with the month preceding the first month in which any of the following occurs: she remarries, dies, becomes entitled to an old-age insurance benefit equal to or exceeding the primary insurance amount (as determined after application of subparagraphs (B) and (C) of paragraph (2)) of such deceased individual, or, if she became entitled to such benefits before she attained age 60, subject to section 423(e) of this title , the termination month (unless she attains retirement age (as defined in section 416( l ) of this title) on or before the last day of such termination month). For purposes of the preceding sentence, the termination month for any individual shall be the third month following the month in which her disability ceases; except that, in the case of an individual who has a period of trial work which ends as determined by application of section 422(c)(4)(A) of this title , the termination month shall be the earlier of (I) the third month following the earliest month after the end of such period of trial work with respect to which such individual is determined to no longer be suffering from a disabling physical or mental impairment, or (II) the third month following the earliest month in which such individual engages or is determined able to engage in substantial gainful activity, but in no event earlier than the first month occurring after the 36 months following such period of trial work in which she engages or is determined able to engage in substantial gainful activity.