$11.$ Which statement concerning brand value is true?

a$)$ Brand value measures the behavioral effect of brand knowledge.

b$)$ Brand equity measures the behavioral effect of brand knowledge.

c$)$ Brand dispersion measures the financial effect of the brand from the company's perspective.

d$)$ Doubling brand dispersion doubles the company's abnormal value.

e$)$ Doubling brand dispersion doubles the company's idiosyncratic stock market risk.