Which of the Phrases Below Completes the Statement

Which of the phrases below completes the statement? ?
Audit sampling is the application of audit procedures to __________ such that all sampling units have a chance of selection in order to provide the auditor with a reasonable basis on which to draw conclusions about the entire population.

A) Documents judged to be significant.
B) Source documents such as sales invoices.
C) Less than 100 per cent of items within a population of relevant items.
D) All of the items within a population of relevant items.