Research Has Consistently Shown Firms That Achieve Both Cost and Differentiation

Research has consistently shown firms that achieve both cost and differentiation advantages tend to perform

A) at about the same level as firms that achieve either cost or differentiation advantages.
B) about the same as firms that are "stuck-in-the-middle."
C) lower than firms that achieve differentiation advantages but higher than firms that achieve cost advantages.
D) higher than firms that achieve either a cost or a differentiation advantage.