A client asks Ellen, a tax practitioner, to provide tax advisory services. Which statement best describes an activity that would illustrate the application of due professional care under the AICPA Code of Professional Conduct?

1- Ellen will base her conclusions on applicable facts and law.

2- Ellen will apply to be an IRS enrolled agent.

3- Ellen will charge the client on a contingent fee basis.

4- Ellen will have a written agreement for this engagement.