The correct answer is (b) 2 years.
According to the Hindu Marriage Act, 1955, a petition for divorce by mutual consent may be presented if the spouses have been living separately for a period of not less than two years. The petition must be filed jointly by both spouses and must be accompanied by a joint statement of the reasons for the divorce. The court may grant the divorce if it is satisfied that the marriage has irretrievably broken down.
Option (a) is incorrect because the minimum period of separation required for a divorce by mutual consent is two years, not one year.
Option (c) is incorrect because the minimum period of separation required for a divorce by mutual consent is two years, not three years.
Option (d) is incorrect because the minimum period of separation required for a divorce by mutual consent is two years.