The following is a list of documents the auditors examined on a recent audit of the purchasing function of a large drug retailer:

Supplier contracts.

• A sample of customer receipts.

• A sample of purchase orders.

• Resumes of inventory clerks.

• Flowcharts of purchasing transactions, including internal controls.

• A written description of purchasing operations for the company.

Required:

Identify which of the documents are most likely to have been examined as part of (a)

the on-site tour,

(b) the preliminary survey,

(c) neither of the two, or

(d) both the onsite tour and the preliminary survey.