For the past two years, a cellphone manufacturer has been selling to a group of distributors, who then sell the products to retailers to sell to the general public. The firm has now informed its distributors that each of them must sell the cellphones for a minimum price the manufacturer has set. In these circumstances, Question 18 options: a) any resulting agreement to give dealers exclusive distribution rights is illegal. b) any resulting minimum resale price maintenance agreements will be illegal. c) the purpose of this contract is to encourage competition between the distributors. d) these tie-in sales encourage competition between the manufacturer's distributors