The three main areas in the value chain where significant differences in the costs of competing firms can occur include
a)age of plants and equipment, number of employees, and advertising costs.
b)operating-level activities, functional area activities, and line of business activities.
c)the nature and make-up of their own internal operations, the activities performed by suppliers, and the activities performed by wholesale distribution and retailing allies.
d)human resource activities (particularly labor costs), vertical integration activities, and strategic partnership activities.
e)variable cost activities, fixed cost activities, and administrative activities.