【单选题】Al sells his business to Dan and, as part of the agreement, promises not to engage in a business of the same kind within thirty miles for three years. Competition within thirty miles would hurt Dan's ...
A.
violates public policy, because it is part of the sale of a business.
B.
violates public policy, because it unreasonably restrains Al from competing.
C.
does not violate public policy, because it is no broader than necessary.