Shown below is Figure $3$ from the paper entitled The Fall of Enron, by Healy and Palepu. Explain how a$)$ external auditors, b$)$ internal auditors, c$)$ the audit committee, and d$)$ C$-$level managers $($CFOs and CEOS$)$ have taken steps, by choice or by regulatory mandate, to increase the standards of corporate ERM since $2000.$