Which of the following statements is true regarding encouraging ethical behavior?

a$.$ Whistle$-$blowing creates ethical problems as employees are afraid to act for fear that they may be reported for something another employee perceives to be unethical even though it is well within the company's legal requirements.

b$.$ Individual companies write codes of conduct that cover every aspect of ethical behavior on the job through broadly applied principles.

c$.$ The government can encourage ethical behavior in business by enacting more stringent regulations such as the Sarbanes$-$Oxley Act of $2002.$

d$.$ Trade associations rarely provide ethical guidelines for their members or exert pressure on members to stop engaging in questionable business practices because their role is to encourage employment of their members$$not tell them how to act when working for their employers.