To avoid potential errors and fraud, well-designed internal control in the accounts payable area should include a segregation of which of the following functions?

Invoice verification and merchandise ordering.

Both processes helps to detect potential error in an order before it is granted.

Explanation:

Invoice verification involves confirming that an invoice has gotten to the department for scanning, processing, such invoice is verified before advance is given. The purpose of verifying an invoice is to be sure that it is accurate and there is no problem or dispute with the invoice.

merchandise ordering: is also known as merchandise buyers, it is the purchase for product or goods made for the purpose of wholesales or retails by a merchandise, such order shows item identification, delivery dates, quantities, specified payment terms, and other conditions which shows the authenticity of the order.