Which statement is most appropriate?

a. Statistical sampling is not a mandatory technique although it should not be ignored by the auditor as it can be used to comment on a system through the use of a relatively small sample. The audit department should define a clear policy on the use of this technique and where and how it should be applied, and this should appear in the audit manual.

b. Statistical sampling is a mandatory technique that should not be ignored by the auditor as it can be used to comment on a system through the use of a relatively small sample. The audit department should define a clear policy on the use of this technique and where and how it should be applied, and this should appear in the audit manual.

c. Statistical sampling is not a mandatory technique although it should not be ignored by the auditor as it can be used to comment on a system through the use of large samples. The audit department should define a clear policy on the use of this technique and where and how it should be applied, and this should appear in the audit manual.

d. Statistical sampling is not a mandatory technique although it should not be ignored by the auditor as it can be used to comment on a system through the use of a relatively small sample. The audit department should define a clear policy on the use of this technique and make sure it is always applied, and this should appear in the audit manual.