Figure 5. How Do Companies Estimate the Cost of Equity? This figure displays CFO responses to the following question: How do you determine your firm's cost of equity capital? {0= Never, 1,2,3,4= Always }. The percent who answered 3 or 4 are presented. CFOs are asked this question only if they first answered "Yes" to the question: Does your firm estimate the cost of equity capital? \{Yes, No . The blue bars display results for the 2022 Duke CFO survey (March 2020 wave); the orange bars display results from Graham and Harvey (2001). Within each blue and orange bar, the solid portion displays responses for large firms (revenue above $1 billion), and the white, crosshatched portion displays responses for small firms (revenue below $1 billion). In 2022, for example, 83% of large firms ( 29% of small firms) always or almost use the Capital Asset Pricing Model (CAPM) to estimate their firm's cost of equity capital. a) What category had the most significant increase in usage between 2001 and 2022 ? (For example, the same percentage of small companies used the Multi-factor models in both time periods) b) Why do you think this change occurred? c) What categories had the most significant decline? d) Why do you think these changes occurred