The correct answer is Ila.

Ila in its primitive sense signifies a 'vow'. It is when a person swears that he will not have sexual intercourse with his wife and abstains from it for four months; an irreversible divorce is effected on its termination.

If intercourse is had within a period of four months, the Ila shall lapse but he has to atone for breaking his oath. Where the husband having made Ila abstains from having intercourse with his wife for four months, the marriage is dissolved with the same legal results, as if there had been an irrevocable divorce pronounced by the husband.