please give full answer starting with an issue and fully explaned terms.

Ad and Bookem, an accounting firm operating nationally over a long period of years, with branch offices in all major cities and coverage of all major industrial areas in the United States, acquired the entire practice and goodwill of Sub and Div. another accounting firm operating nationally, with branch offices in all major cities. The price was to be paid in ten annual installments. The agreement contained a provision that provided that the five major partners of Sub and Div, both individually and as members of the accounting firm, were not to engage in practice anywhere in the United States for three years. (a) Is the provision enforceable? Explain. (b) Assuming the provision is enforceable, what remedies does Ad and Bookem have against any of the partners who breach the contract provision? Explain.