2. A pension scheme is a “defined benefits scheme” if—
(a)the scheme provides for all members to be paid retirement income beginning at normal pension age and continuing for life,
(b)there is a full pensions promise in relation to the retirement income and any other retirement benefits that may be provided to members,
(c)the normal pension age in relation to the retirement income and any other retirement benefits that may be provided to members is fixed, and
(d)such other requirements as may be specified in regulations are met.