What is true about the excess return period?

a It is the period in which a firm is able to earn returns on new investments that are greater than its cost of capital due to competitive advantage of the firm over others

b A higher cost of capital will result in a company having a lower excess return period

c Strong economies of scale typically mean a lower excess return period

d The excess return period is the timeframe historically that a company was able to outperform the market

e The intrinsic value of a company will be lower if it has a higher excess return period