Which of the following statements is not true with respect to audit committees?

a. Individuals not on a firms board of directors should comprise the audit committee.

b. The audit committee generally helps in resolving conflicts between the auditors and company management.

c. All companies listed on the NYSE are required to have an audit committee.

d. Audit committees are required for all companies.

The answer of this question is Dbut I think A is also correct. The book said An audit committee is a selected number of members of a companys board of directors whose responsibilities include helping auditors remain independent of management. So I am confused that whether an audit committee is comprised of the member in board of directors or not?