Which of the following statements concerning the auditor's use of statistical sampling is correct?

Multiple Choice

A classical variables sample needs to be designed with special considerations to include negative balances in the sample.

The selection of zero balances usually does not require special sample design considerations when using monetary$-$unit sampling.

An auditor needs to estimate the dollar amount of the standard deviation of the population in order to use classical variables sampling.

An assumption of monetary$-$unit sampling is that the underlying accounting population is normally distributed.