Which of the following is not a ground of dissolution of marriage under the Hindu Marriage Act, 1955 ?

"Pre-marriage pregnancy of wife." by another person is a ground for a decree of nullity (voidable marriage) under s.12 of the Hindu Marriage Act, 1955, not a ground of divorce, whereas non-resumption of cohabitation after judicial separation, renunciation of the world and pre-Act bigamy are recognised grounds of dissolution.