Which of the Following Examples of a Covenant in Restraint

Which of the following examples of a covenant in restraint of trade is most likely to be contrary to public policy and therefore invalid?

A) A high-tech firm requires its engineers to contractually promise that, during their terms of employment, they will not reveal any information about patents to any other high-tech, communications, or pharmaceutical companies.
B) Partners in an advertising agency contractually promise that, during their time with the partnership, they will engage in advertising sales exclusively for the agency.
C) A contract for the sale and purchase of a business prohibits the vendors from directly competing with their former company for a period of two years.
D) A contract for the sale and purchase of a bakery requires the sellers to promise that they will never own or operate another bakery anywhere in the world.
E) A franchisor requires a franchisee to conduct the franchise operations solely in accordance with the written franchise agreement and not in any other manner.