Salads 'R' Us requires all its franchisees to sign an agreement that they will use napkins and dressings purchased from Salads 'R' Us. Unless the agreement is signed, no one is awarded a franchise. Salads 'R' Us maintains that the agreement is necessary to preserve uniformity and quality in all franchise outlets. The purchasing requirement is:

	a.	an illegal tying arrangement.
	b.	valid as a quality control mechanism for protection of goodwill.
	c.	coercion and is invalid.
	d.	none of the above