Choice "C" is correct. Inclusion of zero and negative balances requires special design considerations with PPS sampling, but it does not require special design considerations with classical variables sampling.
Choice "a" is incorrect. An estimate of the standard deviation of the population's recorded amounts is required for classical variables sampling, but not for PPS sampling.
Choice "b" is incorrect. The auditor is less likely to need a computer program to design an efficient sample for PPS sampling than for classical variables sampling.
Choice "d" is incorrect. Any amount that is individually significant is more likely to be identified and selected when using PPS sampling than when using classical variables sampling.
