For purposes of subchapter L, section
72 (relating to annuities), and section
7702
(a) (relating to definition of life insurance contract), a variable contract (other than a pension plan contract) which is otherwise described in this section and which is based on a segregated asset account shall not be treated as an annuity, endowment, or life insurance contract for any period (and any subsequent period) for which the investments made by such account are not, in accordance with regulations prescribed by the Secretary, adequately diversified.