On November 1, 2017, Hunter opened a sandwich shop in Northridge across the street from a sandwich shop run by Donald. Donald's sandwich shop had been in business for 10 years and had made between $5,000 -$10,000 per year in bad times, and $100,000 - $200,000 profit per year in good times. Disturbed by this new competition, Donald entered into a written agreement to pay Hunter the sum of $50,000, in exchange for Hunter's promise to quit his business and not to open any kind of restaurant whatsoever anywhere in the State of California for 5 years, beginning January 1, 2018. 

(A) Is this contract legal and enforceable? Explain why or why not in detail.

(B) Assume the contract is not enforceable. How might Hunter and Donald restructure it to increase its chances of being legal? Discuss completely.

(C) Assume the contract is enforceable. On December 20, 2017, Hunter tells Donald hat he wants another $25,000 in order to live up to his contractual promise to quit his business across the street. On January 1, Donald reluctantly agrees to pay Hunter another $25,000 (for the total sum of $75,000). If Donald later refuses to pay Hunter the extra $25,000, may Hunter sue Donald for breach of contract? Why or why not?