For a shared core value chain activity, recognized as a core competency in both of their strategies, Witty Walter's learning curve is steeper than that of their rival Clever Clarissa. Assuming they are direct rivals pursuing the same opportunities, what does this imply?

a. Witty Walter is at a disadvantage when compared to Clever Clarissa.

b. Witty Walter is at an advantage when compared to Clever Clarissa.

c. Witty Walter is experiencing negative returns to scale.

d. Witty Walter and Clever Clarissa have achieved competitive parity.

Please explain why other options is incorrect