The correct option is A Insanity
According to Section 44 of Indian Partnership Act, 1932, when a partner becomes of unsound mind and is unable to continue further then other partner can suit in the court for dissolution. Insanity can be a ground for dissolution. Marriage of a partner does not affect the working of partnership. So it can not be a ground for dissolution. Death of a partner does not result in dissolution of firm because remaining partner can continue the business.