A client representation letter is a written statement from a non$-$independent source and therefore

Option A

cannot be regarded as reliable evidence on its own.

Option B

can be regarded as reliable evidence if the high$-$level corporate officials who sign it are trustworthy.

Option C

needs to be confirmed by an outside, independent source such as a financial institution or law firm.

Option D

can be regarded as reliable evidence only if the auditor finds strong internal controls