A is the association of two or more people carrying on a business as co-owners for profit

The answer is a partnership.

Partners in a business may be individuals, businesses or firms. The main reason why organizations partner is to increase their chances of achieving their goals and reaching their targets. In any partnership, every partner must invest, and usually the profit f each partner is based on his contribution. There are three main types of partnerships; general partnerships, limited partnerships, and limited liability partnerships. General partnerships are those partnerships where involved parties have equal responsibilities and share risks and rewards. Limited partnerships are those that an individual with higher status takes sole responsibility for liabilities, whereas the limited partner takes less risk. In a limited liability partnership, the partnership is liable to debts and not individuals.