The correct option is D All of the above
Every act of the partners must be done according and related to the firm. Partner is an agent of the firm and his other partners for the purpose of the business of the partnership, and the acts of every partner who does any act for carrying on in the usual way business of the kind carried on by the firm of which he is a member bind the firm and his partners, so it should be done according to the business. An act or instrument relating to the business of the firm done or executed in the firm name, or in any other manner showing an intention to bind the firm, by any person there to authorised, whether a partner or not, is binding on the firm and all the partners.