2. Pottery Plant Co. has entered into an agreement to buy its actual requirements of potting soil for six months from Green Supplies, a garden supply company. Green Supplies has agreed to sell all the potting soil they will require for six months. The agreement between the two companies is: A. Unenforceable because it is too indefinite as to quantity. B. Unenforceable because it lacks mutuality of obligation. C. Unenforceable because it is illusory. D. A valid and enforceable contract