According to ICH GCP which of the following points should a sponsor consider regarding the selection and qualification of auditors?

1) The sponsor should appoint individuals who are independent of the clinical trials/systems to conduct audits

2) The sponsor should ensure that individuals have no conflict of interest issues prior to the audit

3) The sponsor should appoint individuals who have documented GCP Auditing Certification

4) The sponsor should ensure that the auditors are qualified by training and experience to conduct audits properly. An auditor's qualifications should be documented

Which of the following answers is correct.