Which of the following is a requirement of the Sarbanes$-$Oxley Act?

a$.$ Companies can continue with operations only if they are profitable.

b$.$ External auditors must provide an annual report on the profitability of the company.

c$.$ Companies must prepare an annual report on estimated loss for the next ten years.

d$.$ Companies and their independent accountants must prepare an annual report on the effectiveness of the company's internal controls.