Of the following four items, which one can be found in Circular 230, Subpart B on the list of practitioner duties and restrictions?

a. Complete returns only when the practitioner has appropriate level of knowledge and skill

b. Meet continuing education (CE) requirements

c. Show the taxpayer the completed return before asking them to sign it

d. Document the questions they asked and the taxpayer's answers pertaining to the income that is adventageous for EITC